Name	Known for
Siân Phillips Nain Nain See fewer	Dune (1984)
Gareth Thomas Mr. Llewelyn Mr. Llewelyn See fewer	Blake's 7 (1978)
Osian Roberts Gwyn Gwyn See fewer	Emlyn's Moon (1990)
Lucy Donovan Nia Nia See fewer	The Chestnut Soldier (1991)
Steffan Morris Emlyn Emlyn See fewer	Torchwood (2006)
Jill Richards Mrs. Lloyd Mrs. Lloyd See fewer	Very Annie Mary (2001)
Glan Davies Mr. Lloyd Mr. Lloyd See fewer	Coming Up Roses (1986)
Robert Blythe Mr. Griffiths Mr. Griffiths See fewer	High Hopes (2002)
Sharon Morgan Mrs. Griffiths Mrs. Griffiths See fewer	Apostle (2018)
Ann Queensberry Miss Oliver Miss Oliver See fewer	City of Ember (2008)
Manon Jones Nerys Nerys See fewer	Emlyn's Moon (1990)
Stephanie Hull Catrin Catrin See fewer	Emlyn's Moon (1990)
Gareth Pritchard Alun Alun See fewer	Screen One (1985)
Adam Orr Ewing Siôn Siôn See fewer	Wendy (2013)
Diggory Orr Ewing Gareth Gareth See fewer	The Chestnut Soldier (1991)
Alun Horan Iolo Iolo See fewer	The Chestnut Soldier (1991)