diff --git a/pandas/core/arrays/string_.py b/pandas/core/arrays/string_.py
index de129df2575d3..9b1f986a7158e 100644
--- a/pandas/core/arrays/string_.py
+++ b/pandas/core/arrays/string_.py
@@ -28,7 +28,10 @@
     pa_version_under10p1,
 )
 from pandas.compat.numpy import function as nv
-from pandas.util._decorators import doc
+from pandas.util._decorators import (
+    doc,
+    set_module,
+)
 from pandas.util._exceptions import find_stack_level
 
 from pandas.core.dtypes.base import (
@@ -86,6 +89,7 @@
     from pandas import Series
 
 
+@set_module("pandas")
 @register_extension_dtype
 class StringDtype(StorageExtensionDtype):
     """
diff --git a/pandas/tests/api/test_api.py b/pandas/tests/api/test_api.py
index 25285a451bb3f..00b0236c236c0 100644
--- a/pandas/tests/api/test_api.py
+++ b/pandas/tests/api/test_api.py
@@ -405,6 +405,7 @@ def test_set_module():
     assert pd.IntervalDtype.__module__ == "pandas"
     assert pd.SparseDtype.__module__ == "pandas"
     assert pd.ArrowDtype.__module__ == "pandas"
+    assert pd.StringDtype.__module__ == "pandas"
     assert pd.Index.__module__ == "pandas"
     assert pd.CategoricalIndex.__module__ == "pandas"
     assert pd.DatetimeIndex.__module__ == "pandas"