diff --git a/tools/generate_torch_version.py b/tools/generate_torch_version.py
index ce92638c859e..ec16bbf4546e 100644
--- a/tools/generate_torch_version.py
+++ b/tools/generate_torch_version.py
@@ -1,11 +1,13 @@
 from __future__ import annotations
 
 import argparse
+import email
 import os
 import re
 import subprocess
 from pathlib import Path
 
+from packaging.version import Version
 from setuptools import distutils  # type: ignore[import,attr-defined]
 
 
@@ -48,19 +50,60 @@ def get_tag(pytorch_root: str | Path) -> str:
 
 
 def get_torch_version(sha: str | None = None) -> str:
-    pytorch_root = Path(__file__).absolute().parent.parent
-    version = open(pytorch_root / "version.txt").read().strip()
+    """Determine the torch version string.
 
+    The version is determined from one of the following sources, in order of
+    precedence:
+    1. The PYTORCH_BUILD_VERSION and PYTORCH_BUILD_NUMBER environment variables.
+       These are set by the PyTorch build system when building official
+       releases. If built from an sdist, it is checked that the version matches
+       the sdist version.
+    2. The PKG-INFO file, if it exists. This file is included in source
+       distributions (sdist) and contains the version of the sdist.
+    3. The version.txt file, which contains the base version string. If the git
+       commit SHA is available, it is appended to the version string to
+       indicate that this is a development build.
+    """
+    pytorch_root = Path(__file__).absolute().parent.parent
+    pkg_info_path = pytorch_root / "PKG-INFO"
+    if pkg_info_path.exists():
+        with open(pkg_info_path) as f:
+            pkg_info = email.message_from_file(f)
+        sdist_version = pkg_info["Version"]
+    else:
+        sdist_version = None
     if os.getenv("PYTORCH_BUILD_VERSION"):
         assert os.getenv("PYTORCH_BUILD_NUMBER") is not None
         build_number = int(os.getenv("PYTORCH_BUILD_NUMBER", ""))
         version = os.getenv("PYTORCH_BUILD_VERSION", "")
         if build_number > 1:
             version += ".post" + str(build_number)
-    elif sha != UNKNOWN:
-        if sha is None:
-            sha = get_sha(pytorch_root)
-        version += "+git" + sha[:7]
+        origin = "PYTORCH_BUILD_{VERSION,NUMBER} env variables"
+    elif sdist_version:
+        version = sdist_version
+        origin = "PKG-INFO"
+    else:
+        version = open(pytorch_root / "version.txt").read().strip()
+        origin = "version.txt"
+        if sdist_version is None and sha != UNKNOWN:
+            if sha is None:
+                sha = get_sha(pytorch_root)
+            version += "+git" + sha[:7]
+            origin += " and git commit"
+    # Validate that the version is PEP 440 compliant
+    parsed_version = Version(version)
+    if sdist_version:
+        if (l := parsed_version.local) and l.startswith("git"):
+            # Assume local version is git<sha> and
+            # hence whole version is source version
+            source_version = version
+        else:
+            # local version is absent or platform tag
+            source_version = version.partition("+")[0]
+        assert sdist_version == source_version, (
+            f"Source part '{source_version}' of version '{version}' from "
+            f"{origin} does not match version '{sdist_version}' from PKG-INFO"
+        )
     return version