diff --git a/py/selenium/webdriver/common/proxy.py b/py/selenium/webdriver/common/proxy.py
index 328a3a46ce464..187f00418a421 100644
--- a/py/selenium/webdriver/common/proxy.py
+++ b/py/selenium/webdriver/common/proxy.py
@@ -14,8 +14,11 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
+
 """The Proxy implementation."""
 
+import warnings
+
 
 class ProxyTypeFactory:
     """Factory for proxy types."""
@@ -28,8 +31,8 @@ def make(ff_value, string):
 class ProxyType:
     """Set of possible types of proxy.
 
-    Each proxy type has 2 properties:    'ff_value' is value of Firefox
-    profile preference,    'string' is id of proxy type.
+    Each proxy type has 2 properties: 'ff_value' is value of Firefox
+    profile preference, 'string' is id of proxy type.
     """
 
     DIRECT = ProxyTypeFactory.make(0, "DIRECT")  # Direct connection, no proxy (default on Windows).
@@ -63,6 +66,14 @@ def __get__(self, obj, cls):
     def __set__(self, obj, value):
         if self.name == "autodetect" and not isinstance(value, bool):
             raise ValueError("Autodetect proxy value needs to be a boolean")
+        if self.name == "ftpProxy":
+            # TODO: Remove ftpProxy in future version and remove deprecation warning
+            # https://github.com/SeleniumHQ/selenium/issues/15905
+            warnings.warn(
+                "ftpProxy is deprecated and will be removed in the future",
+                DeprecationWarning,
+                stacklevel=2,
+            )
         getattr(obj, "_verify_proxy_type_compatibility")(self.p_type)
         setattr(obj, "proxyType", self.p_type)
         setattr(obj, self.name, value)
@@ -74,7 +85,7 @@ class Proxy:
 
     proxyType = ProxyType.UNSPECIFIED
     autodetect = False
-    ftpProxy = ""
+    ftpProxy = ""  # TODO: Remove ftpProxy in future version and remove deprecation warning
     httpProxy = ""
     noProxy = ""
     proxyAutoconfigUrl = ""
@@ -100,6 +111,7 @@ class Proxy:
     `value`: `str`
     """
 
+    # TODO: Remove ftpProxy in future version and remove deprecation warning
     ftp_proxy = _ProxyTypeDescriptor("ftpProxy", ProxyType.MANUAL)
     """Gets and Sets `ftp_proxy`
 
@@ -244,7 +256,14 @@ def __init__(self, raw=None):
         if raw:
             if "proxyType" in raw and raw["proxyType"]:
                 self.proxy_type = ProxyType.load(raw["proxyType"])
+            # TODO: Remove ftpProxy in future version and remove deprecation warning
+            # https://github.com/SeleniumHQ/selenium/issues/15905
             if "ftpProxy" in raw and raw["ftpProxy"]:
+                warnings.warn(
+                    "ftpProxy is deprecated and will be removed in the future",
+                    DeprecationWarning,
+                    stacklevel=2,
+                )
                 self.ftp_proxy = raw["ftpProxy"]
             if "httpProxy" in raw and raw["httpProxy"]:
                 self.http_proxy = raw["httpProxy"]
@@ -288,6 +307,7 @@ def _verify_proxy_type_compatibility(self, compatible_proxy):
 
     def to_capabilities(self):
         proxy_caps = {"proxyType": self.proxyType["string"].lower()}
+        # TODO: Remove ftpProxy in future version and remove deprecation warning
         proxies = [
             "autodetect",
             "ftpProxy",
diff --git a/py/test/selenium/webdriver/common/proxy_tests.py b/py/test/selenium/webdriver/common/proxy_tests.py
index 6654b5b6c1cbd..df287593f3640 100644
--- a/py/test/selenium/webdriver/common/proxy_tests.py
+++ b/py/test/selenium/webdriver/common/proxy_tests.py
@@ -22,6 +22,8 @@
 
 MANUAL_PROXY = {
     "httpProxy": "some.url:1234",
+    # TODO: Remove ftpProxy in future (currently deprecated)
+    # https://github.com/SeleniumHQ/selenium/issues/15905
     "ftpProxy": "ftp.proxy",
     "noProxy": "localhost, foo.localhost",
     "sslProxy": "ssl.proxy:1234",
@@ -43,6 +45,8 @@
 def test_can_add_manual_proxy_to_options():
     proxy = Proxy()
     proxy.http_proxy = MANUAL_PROXY["httpProxy"]
+    # TODO: Remove ftpProxy in future (currently deprecated)
+    # https://github.com/SeleniumHQ/selenium/issues/15905
     proxy.ftp_proxy = MANUAL_PROXY["ftpProxy"]
     proxy.no_proxy = MANUAL_PROXY["noProxy"]
     proxy.sslProxy = MANUAL_PROXY["sslProxy"]
@@ -98,6 +102,8 @@ def test_can_init_manual_proxy():
 
     assert ProxyType.MANUAL == proxy.proxy_type
     assert MANUAL_PROXY["httpProxy"] == proxy.http_proxy
+    # TODO: Remove ftpProxy in future (currently deprecated)
+    # https://github.com/SeleniumHQ/selenium/issues/15905
     assert MANUAL_PROXY["ftpProxy"] == proxy.ftp_proxy
     assert MANUAL_PROXY["noProxy"] == proxy.no_proxy
     assert MANUAL_PROXY["sslProxy"] == proxy.sslProxy
@@ -123,6 +129,8 @@ def test_can_init_empty_proxy():
     proxy = Proxy()
     assert ProxyType.UNSPECIFIED == proxy.proxy_type
     assert "" == proxy.http_proxy
+    # TODO: Remove ftpProxy in future (currently deprecated)
+    # https://github.com/SeleniumHQ/selenium/issues/15905
     assert "" == proxy.ftp_proxy
     assert "" == proxy.no_proxy
     assert "" == proxy.sslProxy