You can find the List of Standardised Welsh Place-names here.
You can also download the list under an open licence agreement. Further information about the licence and copyright can be found at the bottom of this page.
The Place-names Standardisation Panel follows national guidelines whilst standardising place-names. You can see them here:
© Welsh Language Commissioner (2018)
This list is licenced under the Open Government Licence 3.0 except where otherwise stated.
Contains OS data © Crown copyright and database right 2018.