diff --git a/README.rst b/README.rst
index 6e16b17..9124c93 100644
--- a/README.rst
+++ b/README.rst
@@ -1,5 +1,5 @@
 .. image:: https://github.com/ovh/python-ovh/raw/master/docs/img/logo.png
-           :alt: Python & OVH APIs
+           :alt: Python & OVHcloud APIs
            :target: https://pypi.python.org/pypi/ovh
 
 Lightweight wrapper around OVHcloud's APIs. Handles all the hard work including
@@ -73,9 +73,9 @@ To interact with the APIs, the SDK needs to identify itself using an
 ``application_key`` and an ``application_secret``. To get them, you need
 to register your application. Depending the API you plan to use, visit:
 
-- `OVH Europe <https://eu.api.ovh.com/createApp/>`_
-- `OVH US <https://api.us.ovhcloud.com/createApp/>`_
-- `OVH North-America <https://ca.api.ovh.com/createApp/>`_
+- `OVHcloud Europe <https://eu.api.ovh.com/createApp/>`_
+- `OVHcloud US <https://api.us.ovhcloud.com/createApp/>`_
+- `OVHcloud North-America <https://ca.api.ovh.com/createApp/>`_
 - `So you Start Europe <https://eu.api.soyoustart.com/createApp/>`_
 - `So you Start North America <https://ca.api.soyoustart.com/createApp/>`_
 - `Kimsufi Europe <https://eu.api.kimsufi.com/createApp/>`_
@@ -104,12 +104,15 @@ it looks like:
     ; uncomment following line when writing a script application
     ; with a single consumer key.
     ;consumer_key=my_consumer_key
+    ; uncomment to unable oauth2 authentication
+    ;client_id=my_client_id
+    ;client_secret=my_client_secret
 
 Depending on the API you want to use, you may set the ``endpoint`` to:
 
-* ``ovh-eu`` for OVH Europe API
-* ``ovh-us`` for OVH US API
-* ``ovh-ca`` for OVH North-America API
+* ``ovh-eu`` for OVHcloud Europe API
+* ``ovh-us`` for OVHcloud US API
+* ``ovh-ca`` for OVHcloud North-America API
 * ``soyoustart-eu`` for So you Start Europe API
 * ``soyoustart-ca`` for So you Start North America API
 * ``kimsufi-eu`` for Kimsufi Europe API
@@ -120,8 +123,21 @@ See Configuration_ for more information on available configuration mechanisms.
 .. note:: When using a versioning system, make sure to add ``ovh.conf`` to ignored
           files. It contains confidential/security-sensitive information!
 
-3. Authorize your application to access a customer account
-**********************************************************
+3. Authorize your application to access a customer account using OAuth2
+***********************************************************************
+
+``python-ovh`` supports two forms of authentication:
+* OAuth2, using scopped service accounts, and compatible with OVHcloud IAM
+* application key & application secret & consumer key (covered in the next chapter)
+
+For OAuth2, first, you need to generate a pair of valid ``client_id`` and ``client_secret``: you
+can proceed by [following this documentation](https://help.ovhcloud.com/csm/en-manage-service-account?id=kb_article_view&sysparm_article=KB0059343)
+
+Once you have retrieved your ``client_id`` and ``client_secret``, you can create and edit
+a configuration file that will be used by ``python-ovh``.
+
+4. Authorize your application to access a customer account using custom OVHcloud authentication
+***********************************************************************************************
 
 To allow your application to access a customer account using the API on your
 behalf, you need a **consumer key (CK)**.
@@ -164,7 +180,7 @@ Install a new mail redirection
 ------------------------------
 
 e-mail redirections may be freely configured on domains and DNS zones hosted by
-OVH to an arbitrary destination e-mail using API call
+OVHcloud to an arbitrary destination e-mail using API call
 ``POST /email/domain/{domain}/redirection``.
 
 For this call, the api specifies that the source address shall be given under the
@@ -195,7 +211,7 @@ is only supported with reserved keywords.
 Grab bill list
 --------------
 
-Let's say you want to integrate OVH bills into your own billing system, you
+Let's say you want to integrate OVHcloud bills into your own billing system, you
 could just script around the ``/me/bills`` endpoints and even get the details
 of each bill lines using ``/me/bill/{billId}/details/{billDetailId}``.
 
@@ -359,7 +375,7 @@ You have 3 ways to provide configuration to the client:
 Embed the configuration in the code
 -----------------------------------
 
-The straightforward way to use OVH's API keys is to embed them directly in the
+The straightforward way to use OVHcloud's API keys is to embed them directly in the
 application code. While this is very convenient, it lacks of elegance and
 flexibility.
 
@@ -547,8 +563,8 @@ build HTML documentation:
 Supported APIs
 ==============
 
-OVH Europe
-----------
+OVHcloud Europe
+---------------
 
 - **Documentation**: https://eu.api.ovh.com/
 - **Community support**: api-subscribe@ml.ovh.net
@@ -556,16 +572,16 @@ OVH Europe
 - **Create application credentials**: https://eu.api.ovh.com/createApp/
 - **Create script credentials** (all keys at once): https://eu.api.ovh.com/createToken/
 
-OVH US
-----------
+OVHcloud US
+-----------
 
 - **Documentation**: https://api.us.ovhcloud.com/
 - **Console**: https://api.us.ovhcloud.com/console/
 - **Create application credentials**: https://api.us.ovhcloud.com/createApp/
 - **Create script credentials** (all keys at once): https://api.us.ovhcloud.com/createToken/
 
-OVH North America
------------------
+OVHcloud North America
+---------------------
 
 - **Documentation**: https://ca.api.ovh.com/
 - **Community support**: api-subscribe@ml.ovh.net
diff --git a/ovh/client.py b/ovh/client.py
index 92f5947..789bbc7 100644
--- a/ovh/client.py
+++ b/ovh/client.py
@@ -49,6 +49,7 @@
     BadParametersError,
     Forbidden,
     HTTPError,
+    InvalidConfiguration,
     InvalidCredential,
     InvalidKey,
     InvalidRegion,
@@ -60,8 +61,9 @@
     ResourceExpiredError,
     ResourceNotFoundError,
 )
+from .oauth2 import OAuth2
 
-#: Mapping between OVH API region names and corresponding endpoints
+# Mapping between OVH API region names and corresponding endpoints
 ENDPOINTS = {
     "ovh-eu": "https://eu.api.ovh.com/1.0",
     "ovh-us": "https://api.us.ovhcloud.com/1.0",
@@ -72,9 +74,16 @@
     "soyoustart-ca": "https://ca.api.soyoustart.com/1.0",
 }
 
-#: Default timeout for each request. 180 seconds connect, 180 seconds read.
+# Default timeout for each request. 180 seconds connect, 180 seconds read.
 TIMEOUT = 180
 
+# OAuth2 token provider URLs
+OAUTH2_TOKEN_URLS = {
+    "ovh-eu": "https://www.ovh.com/auth/oauth2/token",
+    "ovh-ca": "https://ca.ovh.com/auth/oauth2/token",
+    "ovh-us": "https://us.ovhcloud.com/auth/oauth2/token",
+}
+
 
 class Client:
     """
@@ -116,18 +125,24 @@ def __init__(
         consumer_key=None,
         timeout=TIMEOUT,
         config_file=None,
+        client_id=None,
+        client_secret=None,
     ):
         """
         Creates a new Client. No credential check is done at this point.
 
-        The ``application_key`` identifies your application while
-        ``application_secret`` authenticates it. On the other hand, the
-        ``consumer_key`` uniquely identifies your application's end user without
-        requiring his personal password.
+        When using OAuth2 authentication, ``client_id`` and ``client_secret``
+        will be used to initiate a 2-Legged OAuth2 flow.
+
+        When using the OVHcloud authentication method, the ``application_key``
+        identifies your application while ``application_secret`` authenticates
+        it. On the other hand, the ``consumer_key`` uniquely identifies your
+        application's end user without requiring his personal password.
 
-        If any of ``endpoint``, ``application_key``, ``application_secret``
-        or ``consumer_key`` is not provided, this client will attempt to locate
-        from them from environment, ~/.ovh.cfg or /etc/ovh.cfg.
+        If any of ``endpoint``, ``application_key``, ``application_secret``,
+        ``consumer_key``, ``client_id`` or ``client_secret`` is not provided,
+        this client will attempt to locate from them from environment,
+        ``~/.ovh.cfg`` or ``/etc/ovh.cfg``.
 
         See :py:mod:`ovh.config` for more information on supported
         configuration mechanisms.
@@ -139,9 +154,11 @@ def __init__(
         180 seconds for connection and 180 seconds for read.
 
         :param str endpoint: API endpoint to use. Valid values in ``ENDPOINTS``
-        :param str application_key: Application key as provided by OVH
-        :param str application_secret: Application secret key as provided by OVH
+        :param str application_key: Application key as provided by OVHcloud
+        :param str application_secret: Application secret key as provided by OVHcloud
         :param str consumer_key: uniquely identifies
+        :param str client_id: OAuth2 client ID
+        :param str client_secret: OAuth2 client secret
         :param tuple timeout: Connection and read timeout for each request
         :param float timeout: Same timeout for both connection and read
         :raises InvalidRegion: if ``endpoint`` can't be found in ``ENDPOINTS``.
@@ -175,6 +192,50 @@ def __init__(
             consumer_key = configuration.get(endpoint, "consumer_key")
         self._consumer_key = consumer_key
 
+        # load OAuth2 data
+        if client_id is None:
+            client_id = configuration.get(endpoint, "client_id")
+        self._client_id = client_id
+
+        if client_secret is None:
+            client_secret = configuration.get(endpoint, "client_secret")
+        self._client_secret = client_secret
+
+        # configuration validation
+        if bool(self._client_id) is not bool(self._client_secret):
+            raise InvalidConfiguration("Invalid OAuth2 config, both client_id and client_secret must be given")
+
+        if bool(self._application_key) is not bool(self._application_secret):
+            raise InvalidConfiguration(
+                "Invalid authentication config, both application_key and application_secret must be given"
+            )
+
+        if self._client_id is not None and self._application_key is not None:
+            raise InvalidConfiguration(
+                "Can't use both application_key/application_secret and OAuth2 client_id/client_secret"
+            )
+        if self._client_id is None and self._application_key is None:
+            raise InvalidConfiguration(
+                "Missing authentication information, you need to provide at least an application_key/application_secret"
+                " or a client_id/client_secret"
+            )
+        if self._client_id and endpoint not in OAUTH2_TOKEN_URLS:
+            raise InvalidConfiguration(
+                "OAuth2 authentication is not compatible with endpoint "
+                + endpoint
+                + " (it can only be used with ovh-eu, ovh-ca and ovh-us)"
+            )
+
+        # when in OAuth2 mode, instantiate the oauthlib client
+        if self._client_id:
+            self._oauth2 = OAuth2(
+                client_id=self._client_id,
+                client_secret=self._client_secret,
+                token_url=OAUTH2_TOKEN_URLS[endpoint],
+            )
+        else:
+            self._oauth2 = None
+
         # lazy load time delta
         self._time_delta = None
 
@@ -524,7 +585,6 @@ def raw_call(self, method, path, data=None, need_auth=True, headers=None):
 
         if headers is None:
             headers = {}
-        headers["X-Ovh-Application"] = self._application_key
 
         # include payload
         if data is not None:
@@ -533,6 +593,9 @@ def raw_call(self, method, path, data=None, need_auth=True, headers=None):
 
         # sign request. Never sign 'time' or will recurse infinitely
         if need_auth:
+            if self._oauth2:
+                return self._oauth2.session.request(method, target, headers=headers, data=body, timeout=self._timeout)
+
             if not self._application_secret:
                 raise InvalidKey("Invalid ApplicationSecret '%s'" % self._application_secret)
 
@@ -551,4 +614,5 @@ def raw_call(self, method, path, data=None, need_auth=True, headers=None):
             headers["X-Ovh-Timestamp"] = now
             headers["X-Ovh-Signature"] = "$1$" + signature.hexdigest()
 
+        headers["X-Ovh-Application"] = self._application_key
         return self._session.request(method, target, headers=headers, data=body, timeout=self._timeout)
diff --git a/ovh/config.py b/ovh/config.py
index 6e7d15a..4e604fc 100644
--- a/ovh/config.py
+++ b/ovh/config.py
@@ -49,6 +49,8 @@
     application_key=my_app_key
     application_secret=my_application_secret
     consumer_key=my_consumer_key
+    client_id=my_client_id
+    client_secret=my_client_secret
 
 The client will successively attempt to locate this configuration file in
 
diff --git a/ovh/exceptions.py b/ovh/exceptions.py
index 6109d74..d622af3 100644
--- a/ovh/exceptions.py
+++ b/ovh/exceptions.py
@@ -59,6 +59,10 @@ class InvalidCredential(APIError):
     """Raised when trying to sign request with invalid consumer key"""
 
 
+class InvalidConfiguration(APIError):
+    """Raised when trying to load an invalid configuration into a client"""
+
+
 class InvalidResponse(APIError):
     """Raised when api response is not valid json"""
 
@@ -101,3 +105,7 @@ class Forbidden(APIError):
 
 class ResourceExpiredError(APIError):
     """Raised when requested resource expired."""
+
+
+class OAuth2FailureError(APIError):
+    """Raised when the OAuth2 workflow fails"""
diff --git a/ovh/oauth2.py b/ovh/oauth2.py
new file mode 100644
index 0000000..3663a05
--- /dev/null
+++ b/ovh/oauth2.py
@@ -0,0 +1,119 @@
+# Copyright (c) 2013-2024, OVH SAS.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#  * Neither the name of OVH SAS nor the
+#    names of its contributors may be used to endorse or promote products
+#    derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY OVH SAS AND CONTRIBUTORS ````AS IS'' AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL OVH SAS AND CONTRIBUTORS BE LIABLE FOR ANY
+# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""
+Thanks to https://github.com/requests/requests-oauthlib/issues/260
+"""
+
+from oauthlib.oauth2 import BackendApplicationClient, MissingTokenError, OAuth2Error, TokenExpiredError
+from requests_oauthlib import OAuth2Session
+
+from .exceptions import OAuth2FailureError
+
+
+class RefreshOAuth2Session(OAuth2Session):
+    _error = None
+
+    def __init__(self, token_url, **kwargs):
+        self.token_url = token_url
+        super().__init__(**kwargs)
+        self.register_compliance_hook("access_token_response", self.save_error)
+        self.register_compliance_hook("refresh_token_response", self.save_error)
+
+    # This hijacks the
+    def save_error(self, resp):
+        if 200 <= resp.status_code <= 299:
+            self._error = "Received invalid body: " + resp.text
+        if resp.status_code >= 400:
+            self._error = "Token creation failed with status_code={}, body={}".format(resp.status_code, resp.text)
+        return resp
+
+    def fetch_token(self, *args, **kwargs):
+        try:
+            return super().fetch_token(*args, **kwargs)
+        except MissingTokenError as e:
+            desc = "OAuth2 failure: " + e.description
+            if self._error:
+                desc += " " + self._error
+
+            raise OAuth2FailureError(desc) from e
+        except OAuth2Error as e:
+            raise OAuth2FailureError("OAuth2 failure: " + str(e)) from e
+
+    def request(self, *args, **kwargs):
+        try:
+            return super().request(*args, **kwargs)
+        except TokenExpiredError:
+            self.token = self.fetch_token(token_url=self.token_url, **self.auto_refresh_kwargs)
+            self.token_updater(self.token)
+            return super().request(*args, **kwargs)
+
+
+class OAuth2:
+    _session = None
+    _token = None
+
+    def __init__(self, client_id, client_secret, token_url):
+        self.client_id = client_id
+        self.client_secret = client_secret
+        self.token_url = token_url
+
+    def token_updater(self, token):
+        self._token = token
+
+    @property
+    def session(self):
+        if self._session is None:
+            self._session = RefreshOAuth2Session(
+                token_url=self.token_url,
+                client=BackendApplicationClient(
+                    client_id=self.client_id,
+                    scope=["all"],
+                ),
+                token=self.token,
+                token_updater=self.token_updater,
+                auto_refresh_kwargs={
+                    "client_id": self.client_id,
+                    "client_secret": self.client_secret,
+                },
+            )
+        return self._session
+
+    @property
+    def token(self):
+        if self._token is None:
+            self._token = RefreshOAuth2Session(
+                token_url=self.token_url,
+                client=BackendApplicationClient(
+                    client_id=self.client_id,
+                    scope=["all"],
+                ),
+            ).fetch_token(
+                token_url=self.token_url,
+                client_id=self.client_id,
+                client_secret=self.client_secret,
+            )
+        return self._token
diff --git a/setup.cfg b/setup.cfg
index 625976f..6c6ea3b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -35,7 +35,8 @@ setup_requires =
     setuptools>=30.3.0
 # requests: we need ssl+pooling fix from https://docs.python-requests.org/en/latest/community/updates/#id40
 install_requires =
-    requests>=2.11.0
+    requests>=2.31.0
+    requests-oauthlib>=2.0.0
 include_package_data = True
 
 [options.packages.find]
diff --git a/tests/data/user_both.ini b/tests/data/user_both.ini
new file mode 100644
index 0000000..b0fa43a
--- /dev/null
+++ b/tests/data/user_both.ini
@@ -0,0 +1,5 @@
+[ovh-eu]
+application_key=user
+application_secret=user
+client_id=foo
+client_secret=bar
\ No newline at end of file
diff --git a/tests/data/user_oauth2.ini b/tests/data/user_oauth2.ini
new file mode 100644
index 0000000..0501976
--- /dev/null
+++ b/tests/data/user_oauth2.ini
@@ -0,0 +1,3 @@
+[ovh-eu]
+client_id=foo
+client_secret=bar
\ No newline at end of file
diff --git a/tests/data/user_oauth2_incompatible.ini b/tests/data/user_oauth2_incompatible.ini
new file mode 100644
index 0000000..2bfcebb
--- /dev/null
+++ b/tests/data/user_oauth2_incompatible.ini
@@ -0,0 +1,3 @@
+[kimsufi-eu]
+client_id=foo
+client_secret=bar
\ No newline at end of file
diff --git a/tests/data/user_oauth2_invalid.ini b/tests/data/user_oauth2_invalid.ini
new file mode 100644
index 0000000..9d7b564
--- /dev/null
+++ b/tests/data/user_oauth2_invalid.ini
@@ -0,0 +1,3 @@
+[ovh-eu]
+client_id=foo
+client_secret=
\ No newline at end of file
diff --git a/tests/test_client.py b/tests/test_client.py
index efce8e1..070ecbb 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -24,6 +24,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+import time
 from unittest import mock
 
 import pytest
@@ -41,6 +42,7 @@
     NetworkError,
     NotCredential,
     NotGrantedCall,
+    OAuth2FailureError,
     ResourceConflictError,
     ResourceExpiredError,
     ResourceNotFoundError,
@@ -57,7 +59,7 @@ class TestClient:
     @mock.patch("time.time", return_value=1457018875.467238)
     @mock.patch.object(Client, "call", return_value=1457018881)
     def test_time_delta(self, m_call, m_time):
-        api = Client("ovh-eu")
+        api = Client("ovh-eu", MockApplicationKey, MockApplicationSecret)
         assert api._time_delta is None
         assert m_call.called is False
         assert m_time.called is False
@@ -76,7 +78,7 @@ def test_time_delta(self, m_call, m_time):
 
     @mock.patch.object(Client, "call", return_value={"consumerKey": "CK"})
     def test_request_consumerkey(self, m_call):
-        api = Client("ovh-eu")
+        api = Client("ovh-eu", MockApplicationKey, MockApplicationSecret)
         ret = api.request_consumerkey([{"method": "GET", "path": "/"}], "https://example.com", ["127.0.0.1/32"])
 
         m_call.assert_called_once_with(
@@ -92,14 +94,14 @@ def test_request_consumerkey(self, m_call):
         assert ret == {"consumerKey": "CK"}
 
     def test_new_consumer_key_request(self):
-        api = Client("ovh-eu")
+        api = Client("ovh-eu", MockApplicationKey, MockApplicationSecret)
         ck = api.new_consumer_key_request()
         assert ck._client == api
 
     # test wrappers
 
     def test__canonicalize_kwargs(self):
-        api = Client("ovh-eu")
+        api = Client("ovh-eu", MockApplicationKey, MockApplicationSecret)
         assert api._canonicalize_kwargs({}) == {}
         assert api._canonicalize_kwargs({"from": "value"}) == {"from": "value"}
         assert api._canonicalize_kwargs({"_to": "value"}) == {"_to": "value"}
@@ -107,7 +109,7 @@ def test__canonicalize_kwargs(self):
 
     @mock.patch.object(Client, "call")
     def test_query_string(self, m_call):
-        api = Client("ovh-eu")
+        api = Client("ovh-eu", MockApplicationKey, MockApplicationSecret)
 
         for method, call in (("GET", api.get), ("DELETE", api.delete)):
             m_call.reset_mock()
@@ -128,7 +130,7 @@ def test_query_string(self, m_call):
 
     @mock.patch.object(Client, "call")
     def test_body(self, m_call):
-        api = Client("ovh-eu")
+        api = Client("ovh-eu", MockApplicationKey, MockApplicationSecret)
 
         for method, call in (("POST", api.post), ("PUT", api.put)):
             m_call.reset_mock()
@@ -202,7 +204,7 @@ def test_call_query_id(self, m_req):
         m_res.status_code = 99
         m_res.headers = {"X-OVH-QUERYID": "FR.test1"}
 
-        api = Client("ovh-eu", application_key=MockApplicationKey)
+        api = Client("ovh-eu", MockApplicationKey, MockApplicationSecret)
         with pytest.raises(APIError) as e:
             api.call("GET", "/unit/test", None, False)
         assert e.value.query_id == "FR.test1"
@@ -211,7 +213,7 @@ def test_call_query_id(self, m_req):
     def test_call_errors(self, m_req):
         m_res = m_req.return_value
 
-        api = Client("ovh-eu", application_key=MockApplicationKey)
+        api = Client("ovh-eu", MockApplicationKey, MockApplicationSecret)
 
         # request fails, somehow
         m_req.side_effect = requests.RequestException
@@ -246,16 +248,13 @@ def test_call_errors(self, m_req):
                 api.call("GET", "/unauth", None, False)
 
         # errors
-        api = Client("ovh-eu", MockApplicationKey, None, MockConsumerKey)
-        with pytest.raises(InvalidKey):
-            api.call("GET", "/unit/test", None, True)
         api = Client("ovh-eu", MockApplicationKey, MockApplicationSecret, None)
         with pytest.raises(InvalidKey):
             api.call("GET", "/unit/test", None, True)
 
     @mock.patch("ovh.client.Session.request", return_value="Let's assume requests will return this")
     def test_raw_call_with_headers(self, m_req):
-        api = Client("ovh-eu", MockApplicationKey)
+        api = Client("ovh-eu", MockApplicationKey, MockApplicationSecret)
         r = api.raw_call("GET", "/unit/path", None, False, headers={"Custom-Header": "1"})
         assert r == "Let's assume requests will return this"
         assert m_req.call_args_list == [
@@ -274,7 +273,7 @@ def test_raw_call_with_headers(self, m_req):
     # Perform real API tests.
     def test_endpoints(self):
         for endpoint in ENDPOINTS.keys():
-            auth_time = Client(endpoint).get("/auth/time", _need_auth=False)
+            auth_time = Client(endpoint, MockApplicationKey, MockApplicationSecret).get("/auth/time", _need_auth=False)
             assert auth_time > 0
 
     @mock.patch("time.time", return_value=1457018875.467238)
@@ -308,3 +307,104 @@ def _h(prefix):
             mock.call("GET", "https://eu.api.ovh.com/v1/call", headers=_h("v1"), data="", timeout=180),
             mock.call("GET", "https://eu.api.ovh.com/v2/call", headers=_h("v2"), data="", timeout=180),
         ]
+
+    @mock.patch("ovh.client.Session.request")
+    def test_oauth2(self, m_req):
+        def resp(*args, **kwargs):
+            if args[0] == "POST" and args[1] == "https://www.ovh.com/auth/oauth2/token":
+                resp = mock.Mock()
+                resp.status_code = 200
+                resp.text = """{
+  "access_token":"MTQ0NjJkZmQ5OTM2NDE1ZTZjNGZmZjI3",
+  "token_type":"Bearer",
+  "expires_in":3,
+  "scope":"all"
+}"""
+                return resp
+
+            if args[0] == "GET" and args[1] == "https://eu.api.ovh.com/1.0/call":
+                resp = mock.Mock()
+                resp.status_code = 200
+                resp.text = "{}"
+                return resp
+
+            raise NotImplementedError("FIXME")
+
+        m_req.side_effect = resp
+
+        call_oauth = mock.call(
+            "POST",
+            "https://www.ovh.com/auth/oauth2/token",
+            headers={"Accept": "application/json", "Content-Type": "application/x-www-form-urlencoded"},
+            data={"grant_type": "client_credentials", "scope": "all"},
+            files=None,
+            timeout=None,
+            auth=mock.ANY,
+            verify=None,
+            proxies=None,
+            cert=None,
+        )
+        call_api = mock.call(
+            "GET",
+            "https://eu.api.ovh.com/1.0/call",
+            headers={"Authorization": "Bearer MTQ0NjJkZmQ5OTM2NDE1ZTZjNGZmZjI3"},
+            data="",
+            files=None,
+            timeout=180,
+        )
+
+        # First call triggers the fetch of a token, then the real call
+        api = Client("ovh-eu", client_id="oauth2_id", client_secret="oauth2_secret")
+        api.call("GET", "/call", None, True)
+        assert m_req.call_args_list == [call_oauth, call_api]
+
+        # Calling the API again does not trigger the fetch of a new token
+        api.call("GET", "/call", None, True)
+        assert m_req.call_args_list == [call_oauth, call_api, call_api]
+
+        # The fetched token had an `expires_in` set to 3, sleep more than that, which makes us fetch a now token
+        time.sleep(4)
+        api.call("GET", "/call", None, True)
+        assert m_req.call_args_list == [call_oauth, call_api, call_api, call_oauth, call_api]
+
+    @mock.patch("ovh.client.Session.request")
+    def test_oauth2_503(self, m_req):
+        m_res = m_req.return_value
+        m_res.status_code = 503
+        m_res.text = "<html><body><p>test</p></body></html>"
+
+        api = Client("ovh-eu", client_id="oauth2_id", client_secret="oauth2_secret")
+
+        with pytest.raises(OAuth2FailureError) as e:
+            api.call("GET", "/call", None, True)
+        assert str(e.value) == (
+            "OAuth2 failure: Missing access token parameter. Token creation failed with status_code=503, "
+            "body=<html><body><p>test</p></body></html>"
+        )
+
+    @mock.patch("ovh.client.Session.request")
+    def test_oauth2_bad_json(self, m_req):
+        m_res = m_req.return_value
+        m_res.status_code = 200
+        m_res.text = "<html><body><p>test</p></body></html>"
+
+        api = Client("ovh-eu", client_id="oauth2_id", client_secret="oauth2_secret")
+
+        with pytest.raises(OAuth2FailureError) as e:
+            api.call("GET", "/call", None, True)
+        assert str(e.value) == (
+            "OAuth2 failure: Missing access token parameter. Received invalid body: "
+            "<html><body><p>test</p></body></html>"
+        )
+
+    @mock.patch("ovh.client.Session.request")
+    def test_oauth2_unknown_client(self, m_req):
+        m_res = m_req.return_value
+        m_res.status_code = 200
+        m_res.text = '{"error":"invalid_client", "error_description":"ovhcloud oauth2 client does not exists"}'
+
+        api = Client("ovh-eu", client_id="oauth2_id", client_secret="oauth2_secret")
+
+        with pytest.raises(OAuth2FailureError) as e:
+            api.call("GET", "/call", None, True)
+        assert str(e.value) == "OAuth2 failure: (invalid_client) ovhcloud oauth2 client does not exists"
diff --git a/tests/test_config.py b/tests/test_config.py
index bfb6ebc..81801f6 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -24,6 +24,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+from configparser import MissingSectionHeaderError
 import os
 from pathlib import Path
 from unittest.mock import patch
@@ -31,11 +32,16 @@
 import pytest
 
 import ovh
+from ovh.exceptions import InvalidConfiguration, InvalidRegion
 
 TEST_DATA = str(Path(__file__).resolve().parent / "data")
 systemConf = TEST_DATA + "/system.ini"
 userPartialConf = TEST_DATA + "/userPartial.ini"
 userConf = TEST_DATA + "/user.ini"
+userOAuth2Conf = TEST_DATA + "/user_oauth2.ini"
+userOAuth2InvalidConf = TEST_DATA + "/user_oauth2_invalid.ini"
+userOAuth2IncompatibleConfig = TEST_DATA + "/user_oauth2_incompatible.ini"
+userBothConf = TEST_DATA + "/user_both.ini"
 localPartialConf = TEST_DATA + "/localPartial.ini"
 doesNotExistConf = TEST_DATA + "/doesNotExist.ini"
 invalidINIConf = TEST_DATA + "/invalid.ini"
@@ -76,24 +82,58 @@ def test_config_from_only_one_file(self):
 
     @patch("ovh.config.CONFIG_PATH", [doesNotExistConf])
     def test_config_from_non_existing_file(self):
-        client = ovh.Client(endpoint="ovh-eu")
-        assert client._application_key is None
-        assert client._application_secret is None
-        assert client._consumer_key is None
+        with pytest.raises(InvalidConfiguration) as e:
+            ovh.Client(endpoint="ovh-eu")
+
+        assert str(e.value) == (
+            "Missing authentication information, you need to provide at least an "
+            "application_key/application_secret or a client_id/client_secret"
+        )
 
     @patch("ovh.config.CONFIG_PATH", [invalidINIConf])
     def test_config_from_invalid_ini_file(self):
-        from configparser import MissingSectionHeaderError
-
         with pytest.raises(MissingSectionHeaderError):
             ovh.Client(endpoint="ovh-eu")
 
     @patch("ovh.config.CONFIG_PATH", [errorConf])
     def test_config_from_invalid_file(self):
+        with pytest.raises(InvalidConfiguration) as e:
+            ovh.Client(endpoint="ovh-eu")
+
+        assert str(e.value) == (
+            "Missing authentication information, you need to provide at least an "
+            "application_key/application_secret or a client_id/client_secret"
+        )
+
+    @patch("ovh.config.CONFIG_PATH", [userOAuth2Conf])
+    def test_config_oauth2(self):
         client = ovh.Client(endpoint="ovh-eu")
-        assert client._application_key is None
-        assert client._application_secret is None
-        assert client._consumer_key is None
+        assert client._client_id == "foo"
+        assert client._client_secret == "bar"
+
+    @patch("ovh.config.CONFIG_PATH", [userBothConf])
+    def test_config_invalid_both(self):
+        with pytest.raises(InvalidConfiguration) as e:
+            ovh.Client(endpoint="ovh-eu")
+
+        assert str(e.value) == "Can't use both application_key/application_secret and OAuth2 client_id/client_secret"
+
+    @patch("ovh.config.CONFIG_PATH", [userOAuth2InvalidConf])
+    def test_config_invalid_oauth2(self):
+        with pytest.raises(InvalidConfiguration) as e:
+            ovh.Client(endpoint="ovh-eu")
+
+        assert str(e.value) == "Invalid OAuth2 config, both client_id and client_secret must be given"
+
+    @patch("ovh.config.CONFIG_PATH", [userOAuth2IncompatibleConfig])
+    def test_config_incompatible_oauth2(self):
+        with pytest.raises(InvalidConfiguration) as e:
+            ovh.Client(endpoint="kimsufi-eu")
+
+        assert str(e.value) == (
+            "OAuth2 authentication is not compatible with endpoint kimsufi-eu "
+            + "(it can only be used with ovh-eu, ovh-ca and ovh-us)"
+        )
 
     @patch("ovh.config.CONFIG_PATH", [userConf])
     @patch.dict(
@@ -121,7 +161,5 @@ def test_config_from_args(self):
         assert client._consumer_key == "param"
 
     def test_invalid_endpoint(self):
-        from ovh.exceptions import InvalidRegion
-
         with pytest.raises(InvalidRegion):
             ovh.Client(endpoint="not_existing")