diff --git a/.github/workflows/daily.yml b/.github/workflows/daily.yml
index e8d36dbcfe85..516e6a2633b9 100644
--- a/.github/workflows/daily.yml
+++ b/.github/workflows/daily.yml
@@ -35,8 +35,7 @@ jobs:
     strategy:
       matrix:
         os: ["ubuntu-latest", "windows-latest", "macos-latest"]
-        # TODO: unpin the patch versions of Python 3.13/3.14 once stubtest failures are fixed
-        python-version: ["3.10", "3.11", "3.12", "3.13.12", "3.14.3"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
       fail-fast: false
 
     steps:
diff --git a/.github/workflows/stubtest_stdlib.yml b/.github/workflows/stubtest_stdlib.yml
index 99f4c5ff9d6a..db679c9971cd 100644
--- a/.github/workflows/stubtest_stdlib.yml
+++ b/.github/workflows/stubtest_stdlib.yml
@@ -31,8 +31,7 @@ jobs:
     strategy:
       matrix:
         os: ["ubuntu-latest", "windows-latest", "macos-latest"]
-        # TODO: unpin the patch versions of Python 3.13/3.14 once stubtest failures are fixed
-        python-version: ["3.10", "3.11", "3.12", "3.13.12", "3.14.3"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
       fail-fast: false
 
     steps:
diff --git a/stdlib/@tests/stubtest_allowlists/darwin-py313.txt b/stdlib/@tests/stubtest_allowlists/darwin-py313.txt
index bb7f4bba4c2f..681f65781662 100644
--- a/stdlib/@tests/stubtest_allowlists/darwin-py313.txt
+++ b/stdlib/@tests/stubtest_allowlists/darwin-py313.txt
@@ -1,3 +1,13 @@
+# =============
+# 3.13 and 3.14
+# =============
+
+# Starting with Python 3.13.13, these methods accept None for the "scheduler"
+# and "setpgroup" parameters, but would raise a TypeError with Python 3.13.12
+# and earlier. For compatibility reasons, we don't allow None in the stubs.
+os.posix_spawn
+os.posix_spawnp
+
 # =======
 # >= 3.13
 # =======
diff --git a/stdlib/@tests/stubtest_allowlists/darwin-py314.txt b/stdlib/@tests/stubtest_allowlists/darwin-py314.txt
index ddd16a1acb74..b651b2826e49 100644
--- a/stdlib/@tests/stubtest_allowlists/darwin-py314.txt
+++ b/stdlib/@tests/stubtest_allowlists/darwin-py314.txt
@@ -1,3 +1,13 @@
+# =============
+# 3.13 and 3.14
+# =============
+
+# Starting with Python 3.14.4, these methods accept None for the "scheduler"
+# and "setpgroup" parameters, but would raise a TypeError with Python 3.13.12
+# and earlier. For compatibility reasons, we don't allow None in the stubs.
+os.posix_spawn
+os.posix_spawnp
+
 # =========
 # 3.14 only
 # =========
diff --git a/stdlib/@tests/stubtest_allowlists/linux-py313.txt b/stdlib/@tests/stubtest_allowlists/linux-py313.txt
new file mode 100644
index 000000000000..4fccdd15a0b5
--- /dev/null
+++ b/stdlib/@tests/stubtest_allowlists/linux-py313.txt
@@ -0,0 +1,9 @@
+# =============
+# 3.13 and 3.14
+# =============
+
+# Starting with Python 3.13.13, these methods accept None for the "scheduler"
+# and "setpgroup" parameters, but would raise a TypeError with Python 3.13.12
+# and earlier. For compatibility reasons, we don't allow None in the stubs.
+os.posix_spawn
+os.posix_spawnp
diff --git a/stdlib/@tests/stubtest_allowlists/linux-py314.txt b/stdlib/@tests/stubtest_allowlists/linux-py314.txt
index 98f33e427a30..cf414e9a9b3b 100644
--- a/stdlib/@tests/stubtest_allowlists/linux-py314.txt
+++ b/stdlib/@tests/stubtest_allowlists/linux-py314.txt
@@ -1,3 +1,13 @@
+# =============
+# 3.13 and 3.14
+# =============
+
+# Starting with Python 3.14.4, these methods accept None for the "scheduler"
+# and "setpgroup" parameters, but would raise a TypeError with Python 3.13.12
+# and earlier. For compatibility reasons, we don't allow None in the stubs.
+os.posix_spawn
+os.posix_spawnp
+
 # =========
 # 3.14 only
 # =========
diff --git a/stdlib/os/__init__.pyi b/stdlib/os/__init__.pyi
index 4117a9bf74eb..66a9d1dd3bc6 100644
--- a/stdlib/os/__init__.pyi
+++ b/stdlib/os/__init__.pyi
@@ -1532,7 +1532,36 @@ else:
     def WSTOPSIG(status: int) -> int: ...
     def WTERMSIG(status: int) -> int: ...
 
-    if sys.version_info >= (3, 13):
+    if sys.version_info >= (3, 15):
+        def posix_spawn(
+            path: StrOrBytesPath,
+            argv: _ExecVArgs,
+            env: _ExecEnv | None,
+            /,
+            *,
+            file_actions: Sequence[tuple[Any, ...]] | None = (),
+            setpgroup: int | None = None,  # None allowed starting in 3.15
+            resetids: bool = False,
+            setsid: bool = False,
+            setsigmask: Iterable[int] = (),
+            setsigdef: Iterable[int] = (),
+            scheduler: tuple[Any, sched_param] | None = None,  # None allowed starting in 3.15
+        ) -> int: ...
+        def posix_spawnp(
+            path: StrOrBytesPath,
+            argv: _ExecVArgs,
+            env: _ExecEnv | None,
+            /,
+            *,
+            file_actions: Sequence[tuple[Any, ...]] | None = (),
+            setpgroup: int | None = None,  # None allowed starting in 3.15
+            resetids: bool = False,
+            setsid: bool = False,
+            setsigmask: Iterable[int] = (),
+            setsigdef: Iterable[int] = (),
+            scheduler: tuple[Any, sched_param] | None = None,  # None allowed starting in 3.15
+        ) -> int: ...
+    elif sys.version_info >= (3, 13):
         def posix_spawn(
             path: StrOrBytesPath,
             argv: _ExecVArgs,