Owen John Thomas

In November 2020, his book, The Welsh Language in Cardiff : A History of Survival was published by Y Lolfa. The book is an attack on the myth that Cardiff has been an English speaking town since the Anglo-Norman conquest of Cardiff in 1100, emphasising instead that a very significant element of its population have been Welsh speaking throughout history.

In 2020, it was reported that Owen John Thomas was now resident in a care home for people living with dementia.

Thomas was the Plaid Cymru candidate for the Cathays ward in the May 2008 Cardiff local elections, increasing the vote and receiving the highest vote that Plaid Cymru has achieved in that ward. He also ran for that ward in the 1983 local election.

From 1999 to 2007 Thomas was a member of the National Assembly for Wales, representing the South Wales Central region for Plaid Cymru. He was Shadow Minister for Culture at the National Assembly for Wales. Thomas was a firm supporter of Dafydd Wigley's leadership and resisted the challenges against Wigley. Despite his strong convictions that Plaid Cymru had made a mistake in losing Wigley as party leader, Thomas remained loyal to the party whip and its new leader Ieuan Wyn Jones. Thomas faced a strong challenge for the 2003 regional seat selection, but comfortably won the membership vote.

Thomas was a pupil at Marlborough Road School, Cardiff, and at Howardian Grammar School. He left school at sixteen to work in the docks, and had various other jobs including as an analytical chemist. Thomas later attended the Glamorgan College of Education and the University of Wales, Cardiff, where he completed an MA in the history of the Welsh Language. This formed part of his chapter in the book Iaith Carreg fy Aelwyd, published in 1998, and its English language version.

Thomas has been married to Siân Wyn Evans, a former headteacher of Ysgol Glan Morfa, Splott, since 1985. The couple have twin sons. Thomas has three sons and a daughter from a previous marriage. His youngest son, Rhys ab Owen, also a Plaid Cymru politician, was elected on the South Wales Central regional list in the 2021 Senedd election, the same seat Thomas had represented fourteen years earlier. Another son, Rhodri ab Owen, is the Chief Executive of the Cardiff Bay lobbying firm Positif.

Thomas was deputy headteacher of Gladstone Primary School before being elected to the National Assembly for Wales. He is a former chairman of the Cardiff region of the UCAC trade union. Thomas has been active in Plaid Cymru since his teens, filling a variety of posts from branch secretary to vice president. At the 1981 Plaid Cymru Conference, he succeeded in having 'socialism' included amongst the party's main aims. He is a longstanding champion of the campaign for leasehold reform and a founder member of Clwb Ifor Bach (Cardiff's Welsh Language night club), whose president he was from 1983 to 1989. He learned Welsh in his late twenties and played a key role in promoting Welsh medium education in the city, naming several of the schools with historic Cardiff Welsh names.

Owen John Thomas (born 3 October 1939) is a former Plaid Cymru politician who was a Member of the Welsh Assembly (AM) for the South Wales Central region from 1999 to 2007.

Following retirement at the age of 67, Thomas remained active within Plaid Cymru, serving as the party's chair in Cardiff Central and in Cardiff. He is the longest serving trustee of Tŷ'r Cymry, a house given to the Welsh speakers of Cardiff in 1936.