diff --git a/google/pubsub_v1/types/pubsub.py b/google/pubsub_v1/types/pubsub.py
index de29dcd10..93342c8b6 100644
--- a/google/pubsub_v1/types/pubsub.py
+++ b/google/pubsub_v1/types/pubsub.py
@@ -558,6 +558,22 @@ class Subscription(proto.Message):
             ``StreamingPull`` requests will return FAILED_PRECONDITION.
             If the subscription is a push subscription, pushes to the
             endpoint will not be made.
+        enable_exactly_once_delivery (bool):
+            If true, Pub/Sub provides the following guarantees for the
+            delivery of a message with a given value of ``message_id``
+            on this subscription:
+
+            -  The message sent to a subscriber is guaranteed not to be
+               resent before the message's acknowledgement deadline
+               expires.
+            -  An acknowledged message will not be resent to a
+               subscriber.
+
+            Note that subscribers may still receive multiple copies of a
+            message when ``enable_exactly_once_delivery`` is true if the
+            message was published multiple times by a publisher client.
+            These copies are considered distinct by Pub/Sub and have
+            distinct ``message_id`` values.
         topic_message_retention_duration (google.protobuf.duration_pb2.Duration):
             Output only. Indicates the minimum duration for which a
             message is retained after it is published to the
@@ -588,6 +604,7 @@ class Subscription(proto.Message):
     )
     retry_policy = proto.Field(proto.MESSAGE, number=14, message="RetryPolicy",)
     detached = proto.Field(proto.BOOL, number=15,)
+    enable_exactly_once_delivery = proto.Field(proto.BOOL, number=16,)
     topic_message_retention_duration = proto.Field(
         proto.MESSAGE, number=17, message=duration_pb2.Duration,
     )
diff --git a/scripts/fixup_pubsub_v1_keywords.py b/scripts/fixup_pubsub_v1_keywords.py
index ab7623917..039fa1e8f 100644
--- a/scripts/fixup_pubsub_v1_keywords.py
+++ b/scripts/fixup_pubsub_v1_keywords.py
@@ -42,7 +42,7 @@ class pubsubCallTransformer(cst.CSTTransformer):
         'acknowledge': ('subscription', 'ack_ids', ),
         'create_schema': ('parent', 'schema', 'schema_id', ),
         'create_snapshot': ('name', 'subscription', 'labels', ),
-        'create_subscription': ('name', 'topic', 'push_config', 'ack_deadline_seconds', 'retain_acked_messages', 'message_retention_duration', 'labels', 'enable_message_ordering', 'expiration_policy', 'filter', 'dead_letter_policy', 'retry_policy', 'detached', 'topic_message_retention_duration', ),
+        'create_subscription': ('name', 'topic', 'push_config', 'ack_deadline_seconds', 'retain_acked_messages', 'message_retention_duration', 'labels', 'enable_message_ordering', 'expiration_policy', 'filter', 'dead_letter_policy', 'retry_policy', 'detached', 'enable_exactly_once_delivery', 'topic_message_retention_duration', ),
         'create_topic': ('name', 'labels', 'message_storage_policy', 'kms_key_name', 'schema_settings', 'satisfies_pzs', 'message_retention_duration', ),
         'delete_schema': ('name', ),
         'delete_snapshot': ('snapshot', ),
diff --git a/tests/unit/gapic/pubsub_v1/test_subscriber.py b/tests/unit/gapic/pubsub_v1/test_subscriber.py
index 37a208c34..7ba54cc6d 100644
--- a/tests/unit/gapic/pubsub_v1/test_subscriber.py
+++ b/tests/unit/gapic/pubsub_v1/test_subscriber.py
@@ -638,6 +638,7 @@ def test_create_subscription(request_type, transport: str = "grpc"):
             enable_message_ordering=True,
             filter="filter_value",
             detached=True,
+            enable_exactly_once_delivery=True,
         )
         response = client.create_subscription(request)
 
@@ -655,6 +656,7 @@ def test_create_subscription(request_type, transport: str = "grpc"):
     assert response.enable_message_ordering is True
     assert response.filter == "filter_value"
     assert response.detached is True
+    assert response.enable_exactly_once_delivery is True
 
 
 def test_create_subscription_empty_call():
@@ -700,6 +702,7 @@ async def test_create_subscription_async(
                 enable_message_ordering=True,
                 filter="filter_value",
                 detached=True,
+                enable_exactly_once_delivery=True,
             )
         )
         response = await client.create_subscription(request)
@@ -718,6 +721,7 @@ async def test_create_subscription_async(
     assert response.enable_message_ordering is True
     assert response.filter == "filter_value"
     assert response.detached is True
+    assert response.enable_exactly_once_delivery is True
 
 
 @pytest.mark.asyncio
@@ -905,6 +909,7 @@ def test_get_subscription(request_type, transport: str = "grpc"):
             enable_message_ordering=True,
             filter="filter_value",
             detached=True,
+            enable_exactly_once_delivery=True,
         )
         response = client.get_subscription(request)
 
@@ -922,6 +927,7 @@ def test_get_subscription(request_type, transport: str = "grpc"):
     assert response.enable_message_ordering is True
     assert response.filter == "filter_value"
     assert response.detached is True
+    assert response.enable_exactly_once_delivery is True
 
 
 def test_get_subscription_empty_call():
@@ -963,6 +969,7 @@ async def test_get_subscription_async(
                 enable_message_ordering=True,
                 filter="filter_value",
                 detached=True,
+                enable_exactly_once_delivery=True,
             )
         )
         response = await client.get_subscription(request)
@@ -981,6 +988,7 @@ async def test_get_subscription_async(
     assert response.enable_message_ordering is True
     assert response.filter == "filter_value"
     assert response.detached is True
+    assert response.enable_exactly_once_delivery is True
 
 
 @pytest.mark.asyncio
@@ -1130,6 +1138,7 @@ def test_update_subscription(request_type, transport: str = "grpc"):
             enable_message_ordering=True,
             filter="filter_value",
             detached=True,
+            enable_exactly_once_delivery=True,
         )
         response = client.update_subscription(request)
 
@@ -1147,6 +1156,7 @@ def test_update_subscription(request_type, transport: str = "grpc"):
     assert response.enable_message_ordering is True
     assert response.filter == "filter_value"
     assert response.detached is True
+    assert response.enable_exactly_once_delivery is True
 
 
 def test_update_subscription_empty_call():
@@ -1192,6 +1202,7 @@ async def test_update_subscription_async(
                 enable_message_ordering=True,
                 filter="filter_value",
                 detached=True,
+                enable_exactly_once_delivery=True,
             )
         )
         response = await client.update_subscription(request)
@@ -1210,6 +1221,7 @@ async def test_update_subscription_async(
     assert response.enable_message_ordering is True
     assert response.filter == "filter_value"
     assert response.detached is True
+    assert response.enable_exactly_once_delivery is True
 
 
 @pytest.mark.asyncio