diff --git a/Runtimes/Overlay/Android/Android/CMakeLists.txt b/Runtimes/Overlay/Android/Android/CMakeLists.txt
new file mode 100644
index 0000000000000..414836134e385
--- /dev/null
+++ b/Runtimes/Overlay/Android/Android/CMakeLists.txt
@@ -0,0 +1,25 @@
+
+gyb_expand(tgmath.swift.gyb tgmath.swift)
+
+add_library(swiftAndroid
+  tgmath.swift
+  Android.swift
+  Platform.swift
+  POSIXError.swift
+  TiocConstants.swift)
+set_target_properties(swiftAndroid PROPERTIES
+  Swift_MODULE_NAME Android)
+target_compile_definitions(swiftAndroid PRIVATE
+  $<$<BOOL:${SwiftOverlay_ENABLE_REFLECTION}>:SWIFT_ENABLE_REFLECTION>)
+target_link_libraries(swiftAndroid PRIVATE
+  SwiftAndroid
+  swiftCore)
+
+install(TARGETS swiftAndroid
+  ARCHIVE DESTINATION "${SwiftOverlay_INSTALL_LIBDIR}"
+  LIBRARY DESTINATION "${SwiftOverlay_INSTALL_LIBDIR}"
+  RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}")
+emit_swift_interface(swiftAndroid)
+install_swift_interface(swiftAndroid)
+
+embed_manifest(swiftAndroid)
diff --git a/Runtimes/Overlay/Android/CMakeLists.txt b/Runtimes/Overlay/Android/CMakeLists.txt
new file mode 100644
index 0000000000000..8642382b6efe5
--- /dev/null
+++ b/Runtimes/Overlay/Android/CMakeLists.txt
@@ -0,0 +1,4 @@
+
+add_subdirectory(clang)
+add_subdirectory(Android)
+add_subdirectory(Math)
diff --git a/Runtimes/Overlay/Android/Math/CMakeLists.txt b/Runtimes/Overlay/Android/Math/CMakeLists.txt
new file mode 100644
index 0000000000000..abe85dee695a3
--- /dev/null
+++ b/Runtimes/Overlay/Android/Math/CMakeLists.txt
@@ -0,0 +1,17 @@
+
+add_library(swift_math
+  Math.swift)
+set_target_properties(swift_math PROPERTIES
+  Swift_MODULE_NAME math)
+target_link_libraries(swift_math PRIVATE
+  SwiftAndroid
+  swiftCore)
+
+install(TARGETS swift_math
+  ARCHIVE DESTINATION "${SwiftOverlay_INSTALL_LIBDIR}"
+  LIBRARY DESTINATION "${SwiftOverlay_INSTALL_LIBDIR}"
+  RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}")
+emit_swift_interface(swift_math)
+install_swift_interface(swift_math)
+
+embed_manifest(swift_math)
diff --git a/Runtimes/Overlay/Android/clang/CMakeLists.txt b/Runtimes/Overlay/Android/clang/CMakeLists.txt
new file mode 100644
index 0000000000000..517c7eddd2e39
--- /dev/null
+++ b/Runtimes/Overlay/Android/clang/CMakeLists.txt
@@ -0,0 +1,40 @@
+
+# FIXME: how do we determine the sysroot? `CMAKE_SYSROOT` does not contain the sysroot.
+file(CONFIGURE
+  OUTPUT android-ndk-overlay.yaml
+  CONTENT [[
+---
+version: 0
+case-sensitive: false
+use-external-names: false
+roots:
+  - name: "@CMAKE_ANDROID_NDK@/toolchains/llvm/prebuilt/windows-x86_64/sysroot/usr/include"
+    type: directory
+    contents:
+      - name: module.modulemap
+        type: file
+        external-contents: "@CMAKE_CURRENT_SOURCE_DIR@/android.modulemap"
+      - name: SwiftAndroidNDK.h
+        type: file
+        external-contents: "@CMAKE_CURRENT_SOURCE_DIR@/SwiftAndroidNDK.h"
+      - name: SwiftBionic.h
+        type: file
+        external-contents: "@CMAKE_CURRENT_SOURCE_DIR@/SwiftBionic.h"
+]]
+ESCAPE_QUOTES @ONLY NEWLINE_STYLE LF)
+
+add_library(SwiftAndroid INTERFACE)
+target_compile_options(SwiftAndroid INTERFACE
+  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xcc --sysroot=\"${CMAKE_ANDROID_NDK_TOOLCHAIN_UNIFIED}/sysroot\">"
+  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-vfsoverlay ${CMAKE_CURRENT_BINARY_DIR}/android-ndk-overlay.yaml>")
+
+install(FILES
+  android.modulemap
+  SwiftAndroidNDK.h
+  SwiftBionic.h
+  DESTINATION ${CMAKE_INSTALL_LIBDIR}/swift$<$<NOT:$<BOOL:${BUILD_SHARED_LIBS}>>:_static>/${SwiftOverlay_PLATFORM_SUBDIR}/${SwiftOverlay_ARCH_SUBDIR})
+
+install(FILES
+  posix_filesystem.apinotes
+  spawn.apinotes
+  DESTINATION ${CMAKE_INSTALL_LIBDIR}/swift$<$<NOT:$<BOOL:${BUILD_SHARED_LIBS}>>:_static>/apinotes)
diff --git a/Runtimes/Overlay/CMakeLists.txt b/Runtimes/Overlay/CMakeLists.txt
index 030a1c326587d..eef4042942bbc 100644
--- a/Runtimes/Overlay/CMakeLists.txt
+++ b/Runtimes/Overlay/CMakeLists.txt
@@ -50,6 +50,9 @@ add_compile_options(
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xfrontend -disable-implicit-string-processing-module-import>")
 
 add_subdirectory(clang)
+if(ANDROID)
+  add_subdirectory(Android)
+endif()
 if(WIN32)
   add_subdirectory(Windows)
 endif()
diff --git a/Runtimes/Resync.cmake b/Runtimes/Resync.cmake
index 59d95df91d14e..1af913cba5899 100644
--- a/Runtimes/Resync.cmake
+++ b/Runtimes/Resync.cmake
@@ -104,11 +104,35 @@ copy_library_sources("linker-support" "" "Overlay")
 message(STATUS "Clang[${StdlibSources}/public/ClangOverlays] -> ${CMAKE_CURRENT_LIST_DIR}/Overlay/clang")
 copy_files(public/ClangOverlays Overlay/clang FILES float.swift.gyb)
 
+# Android Overlay
+message(STATUS "Android modulemaps[${StdlibSources}/Platform] -> ${CMAKE_CURRENT_LIST_DIR}/Overlay/Android/clang")
+copy_files(public/Platform Overlay/Android/clang
+  FILES
+    android.modulemap
+    posix_filesystem.apinotes
+    spawn.apinotes
+    SwiftAndroidNDK.h
+    SwiftBionic.h)
+
+message(STATUS "Android Android[${StdlibSources}/Platform] -> ${CMAKE_CURRENT_LIST_DIR}/Overlay/Android/Android")
+copy_files(public/Platform Overlay/Android/Android
+  FILES
+    Android.swift
+    Platform.swift
+    POSIXError.swift
+    TiocConstants.swift
+    tgmath.swift.gyb)
+
+message(STATUS "Android Math[${StdlibSources}/Platform] -> ${CMAKE_CURRENT_LIST_DIR}/Overlay/Android/Math")
+copy_files(public/Platform Overlay/Android/Math
+  FILES
+    Math.swift)
+
 # Windows Overlay
 message(STATUS "WinSDK[${StdlibSources}/public/Windows] -> ${CMAKE_CURRENT_LIST_DIR}/Overlay/Windows/WinSDK")
 copy_files(public/Windows Overlay/Windows/WinSDK FILES WinSDK.swift)
 
-message(STATUS "Windows Modulemaps[${StdlibSources}/Platform] -> ${CMAKE_CURRENT_LIST_DIR}/Overlay/Windows/clang")
+message(STATUS "Windows modulemaps[${StdlibSources}/Platform] -> ${CMAKE_CURRENT_LIST_DIR}/Overlay/Windows/clang")
 copy_files(public/Platform Overlay/Windows/clang
   FILES
     ucrt.modulemap