diff --git a/Lib/_bootlocale.py b/Lib/_bootlocale.py
--- a/Lib/_bootlocale.py
+++ b/Lib/_bootlocale.py
@@ -9,21 +9,29 @@ import _locale
 
 if sys.platform.startswith("win"):
     def getpreferredencoding(do_setlocale=True):
         return _locale._getdefaultlocale()[1]
 else:
     try:
         _locale.CODESET
     except AttributeError:
-        def getpreferredencoding(do_setlocale=True):
-            # This path for legacy systems needs the more complex
-            # getdefaultlocale() function, import the full locale module.
-            import locale
-            return locale.getpreferredencoding(do_setlocale)
+        import sysconfig
+        if sysconfig.get_config_var('ANDROID_API_LEVEL'):
+            # On Android langinfo.h and CODESET is missing, and UTF-8 is always
+            # used in mbstowcs and wcstombs
+            def getpreferredencoding(do_setlocale=True):
+                assert not do_setlocale
+                return 'UTF-8'
+        else:
+            def getpreferredencoding(do_setlocale=True):
+                # This path for legacy systems needs the more complex
+                # getdefaultlocale() function, import the full locale module.
+                import locale
+                return locale.getpreferredencoding(do_setlocale)
     else:
         def getpreferredencoding(do_setlocale=True):
             assert not do_setlocale
             result = _locale.nl_langinfo(_locale.CODESET)
             if not result and sys.platform == 'darwin':
                 # nl_langinfo can return an empty string
                 # when the setting has an invalid value.
                 # Default to UTF-8 in that case because
diff --git a/Lib/locale.py b/Lib/locale.py
--- a/Lib/locale.py
+++ b/Lib/locale.py
@@ -613,25 +613,31 @@ if sys.platform.startswith("win"):
         """Return the charset that the user is likely using."""
         import _bootlocale
         return _bootlocale.getpreferredencoding(False)
 else:
     # On Unix, if CODESET is available, use that.
     try:
         CODESET
     except NameError:
-        # Fall back to parsing environment variables :-(
-        def getpreferredencoding(do_setlocale = True):
-            """Return the charset that the user is likely using,
-            by looking at environment variables."""
-            res = getdefaultlocale()[1]
-            if res is None:
-                # LANG not set, default conservatively to ASCII
-                res = 'ascii'
-            return res
+        # Android always uses UTF-8
+        import sysconfig
+        if sysconfig.get_config_var('ANDROID_API_LEVEL'):
+            def getpreferredencoding(do_setlocale = True):
+                return 'UTF-8'
+        else:
+            # Fall back to parsing environment variables :-(
+            def getpreferredencoding(do_setlocale = True):
+                """Return the charset that the user is likely using,
+                by looking at environment variables."""
+                res = getdefaultlocale()[1]
+                if res is None:
+                    # LANG not set, default conservatively to ASCII
+                    res = 'ascii'
+                return res
     else:
         def getpreferredencoding(do_setlocale = True):
             """Return the charset that the user is likely using,
             according to the system configuration."""
             import _bootlocale
             if do_setlocale:
                 oldloc = setlocale(LC_CTYPE)
                 try: