diff --git a/pydantic_ai_slim/pydantic_ai/models/__init__.py b/pydantic_ai_slim/pydantic_ai/models/__init__.py
index f24f836d0..5e483fe34 100644
--- a/pydantic_ai_slim/pydantic_ai/models/__init__.py
+++ b/pydantic_ai_slim/pydantic_ai/models/__init__.py
@@ -313,6 +313,20 @@
         'openai:gpt-4o-mini-search-preview-2025-03-11',
         'openai:gpt-4o-search-preview',
         'openai:gpt-4o-search-preview-2025-03-11',
+        'openai:gpt-5',
+        'openai:gpt-5-mini',
+        'openai:gpt-5-nano',
+        'openai:gpt-5-2025-08-07',
+        'openai:gpt-5-mini-2025-08-07',
+        'openai:gpt-5-nano-2025-08-07',
+        'openai:gpt-5-chat-latest',
+        'gpt-5',
+        'gpt-5-mini',
+        'gpt-5-nano',
+        'gpt-5-2025-08-07',
+        'gpt-5-mini-2025-08-07',
+        'gpt-5-nano-2025-08-07',
+        'gpt-5-chat-latest',
         'openai:o1',
         'openai:o1-2024-12-17',
         'openai:o1-mini',
diff --git a/pydantic_ai_slim/pydantic_ai/models/openai.py b/pydantic_ai_slim/pydantic_ai/models/openai.py
index f15e98b2d..969ee4dc2 100644
--- a/pydantic_ai_slim/pydantic_ai/models/openai.py
+++ b/pydantic_ai_slim/pydantic_ai/models/openai.py
@@ -83,7 +83,19 @@
     'OpenAIModelName',
 )
 
-OpenAIModelName = Union[str, AllModels]
+OpenAIModelName = Union[
+    str,
+    AllModels,
+    Literal[
+        'gpt-5',
+        'gpt-5-mini',
+        'gpt-5-nano',
+        'gpt-5-2025-08-07',
+        'gpt-5-mini-2025-08-07',
+        'gpt-5-nano-2025-08-07',
+        'gpt-5-chat-latest',
+    ],
+]
 """
 Possible OpenAI model names.