diff --git a/CHANGES/9207.feature.rst b/CHANGES/9207.feature.rst
new file mode 100644
index 00000000000..d9ac55c8520
--- /dev/null
+++ b/CHANGES/9207.feature.rst
@@ -0,0 +1 @@
+Added ``proxy`` and ``proxy_auth`` parameters to ``ClientSession`` -- by :user:`meshya`.
diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index 9ab093ae2a7..5ef10dd4993 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -243,6 +243,7 @@ Matthieu Hauglustaine
 Matthieu Rigal
 Matvey Tingaev
 Meet Mangukiya
+Meshya
 Michael Ihnatenko
 Michał Górny
 Mikhail Burshteyn
diff --git a/aiohttp/client.py b/aiohttp/client.py
index 16defeb4801..44366eed92c 100644
--- a/aiohttp/client.py
+++ b/aiohttp/client.py
@@ -252,6 +252,8 @@ class ClientSession:
         "_max_line_size",
         "_max_field_size",
         "_resolve_charset",
+        "_default_proxy",
+        "_default_proxy_auth",
     )
 
     def __init__(
@@ -261,6 +263,8 @@ def __init__(
         connector: Optional[BaseConnector] = None,
         cookies: Optional[LooseCookies] = None,
         headers: Optional[LooseHeaders] = None,
+        proxy: Optional[StrOrURL] = None,
+        proxy_auth: Optional[BasicAuth] = None,
         skip_auto_headers: Optional[Iterable[str]] = None,
         auth: Optional[BasicAuth] = None,
         json_serialize: JSONEncoder = json.dumps,
@@ -361,6 +365,9 @@ def __init__(
 
         self._resolve_charset = fallback_charset_resolver
 
+        self._default_proxy = proxy
+        self._default_proxy_auth = proxy_auth
+
     def __init_subclass__(cls: Type["ClientSession"]) -> None:
         raise TypeError(
             "Inheritance class {} from ClientSession "
@@ -480,6 +487,11 @@ async def _request(
             for i in skip_auto_headers:
                 skip_headers.add(istr(i))
 
+        if proxy is None:
+            proxy = self._default_proxy
+        if proxy_auth is None:
+            proxy_auth = self._default_proxy_auth
+
         if proxy is not None:
             try:
                 proxy = URL(proxy)
diff --git a/docs/client_advanced.rst b/docs/client_advanced.rst
index 0a7093661ff..19a4c196c33 100644
--- a/docs/client_advanced.rst
+++ b/docs/client_advanced.rst
@@ -605,6 +605,13 @@ Authentication credentials can be passed in proxy URL::
    session.get("http://python.org",
                proxy="http://user:pass@some.proxy.com")
 
+And you may set default proxy::
+
+   proxy_auth = aiohttp.BasicAuth('user', 'pass')
+   async with aiohttp.ClientSession(proxy="http://proxy.com", proxy_auth=proxy_auth) as session:
+       async with session.get("http://python.org") as resp:
+           print(resp.status)
+
 Contrary to the ``requests`` library, it won't read environment
 variables by default. But you can do so by passing
 ``trust_env=True`` into :class:`aiohttp.ClientSession`
diff --git a/tests/test_client_session.py b/tests/test_client_session.py
index 30c24a3de39..f8efeac077d 100644
--- a/tests/test_client_session.py
+++ b/tests/test_client_session.py
@@ -710,6 +710,55 @@ async def test_proxy_str(session: ClientSession, params: _Params) -> None:
     ]
 
 
+async def test_default_proxy(loop: asyncio.AbstractEventLoop) -> None:
+    proxy_url = URL("http://proxy.example.com")
+    proxy_auth = mock.Mock()
+    proxy_url2 = URL("http://proxy.example2.com")
+    proxy_auth2 = mock.Mock()
+
+    class OnCall(Exception):
+        pass
+
+    request_class_mock = mock.Mock(side_effect=OnCall())
+    session = ClientSession(
+        proxy=proxy_url, proxy_auth=proxy_auth, request_class=request_class_mock
+    )
+
+    assert session._default_proxy == proxy_url, "`ClientSession._default_proxy` not set"
+    assert (
+        session._default_proxy_auth == proxy_auth
+    ), "`ClientSession._default_proxy_auth` not set"
+
+    with pytest.raises(OnCall):
+        await session.get(
+            "http://example.com",
+        )
+
+    assert request_class_mock.called, "request class not called"
+    assert (
+        request_class_mock.call_args[1].get("proxy") == proxy_url
+    ), "`ClientSession._request` uses default proxy not one used in ClientSession.get"
+    assert (
+        request_class_mock.call_args[1].get("proxy_auth") == proxy_auth
+    ), "`ClientSession._request` uses default proxy_auth not one used in ClientSession.get"
+
+    request_class_mock.reset_mock()
+    with pytest.raises(OnCall):
+        await session.get(
+            "http://example.com", proxy=proxy_url2, proxy_auth=proxy_auth2
+        )
+
+    assert request_class_mock.called, "request class not called"
+    assert (
+        request_class_mock.call_args[1].get("proxy") == proxy_url2
+    ), "`ClientSession._request` uses default proxy not one used in ClientSession.get"
+    assert (
+        request_class_mock.call_args[1].get("proxy_auth") == proxy_auth2
+    ), "`ClientSession._request` uses default proxy_auth not one used in ClientSession.get"
+
+    await session.close()
+
+
 async def test_request_tracing(
     loop: asyncio.AbstractEventLoop, aiohttp_client: AiohttpClient
 ) -> None: