diff --git a/lldb/cmake/modules/FindPythonInterpAndLibs.cmake b/lldb/cmake/modules/FindPythonInterpAndLibs.cmake
--- a/lldb/cmake/modules/FindPythonInterpAndLibs.cmake
+++ b/lldb/cmake/modules/FindPythonInterpAndLibs.cmake
@@ -10,6 +10,8 @@
   find_package(SWIG 2.0)
   if (SWIG_FOUND)
     if ("${CMAKE_SYSTEM_NAME}" STREQUAL "Windows")
+      # Use PYTHON_HOME as a hint to find Python 3.
+      set(Python3_ROOT_DIR PYTHON_HOME)
       find_package(Python3 COMPONENTS Interpreter Development)
       if (Python3_FOUND AND Python3_Interpreter_FOUND)
         set(PYTHON_LIBRARIES ${Python3_LIBRARIES})