Sioned Williams

Sioned Ann Williams (born 14 August 1971) is a Welsh politician who has served as Deputy First Minister of Wales and Cabinet Minister for Social Justice and Equality since 2026. A member of Plaid Cymru, she has been a Member of the Senedd (MS) for Brycheiniog Tawe Nedd, and previously the South Wales West region, since 2021.

Early life Williams was born in Monmouthshire and was educated at Ysgol Gymraeg Cwmbrân and Ysgol Gyfun Cwm Rhymni. She attended Aberystwyth University where she studied Welsh and English. Later, she attended Cardiff University with a S4C T. Glynne Davies Scholarship.

Williams' great uncle Dai Wil, was an agent for Aneurin Bevan in one of his early elections.

Political career The majority of Williams' family were Labour Party supporters, other than her mother, who voted Plaid Cymru "to remind them that we're here". Sioned said that the miners' strike, the Campaign for Nuclear Disarmament and the campaign to establish S4C were all "certainly formative features of my youth".

Sioned is the Plaid Cymru spokesperson for Social Justice and Early Years. She is also a member of the Senedd's committee for Equality and Social Justice, and is Chair of four Senedd Cross Party Groups: the Senedd Cross Party Group on Violence against Women and Children; the Senedd Cross Party Group on Human Rights; the Senedd Cross Party Group on Learning Disability and the Senedd Cross Party Group on Consumer Rights.

As of 2021, Sioned was a Community Councillor for Alltwen and Chair of Cilybebyll Community Council. She previously served as Chair of Governors of Ysgol Gynradd Gymraeg Pontardawe for five years, and then became governor of Ysgol Gymraeg Ystalyfera Bro Dur.

Sioned has campaigned passionately on many matters of social justice and inequality since her election. Notably, she successfully helped to secure a reopening of the enquiry into the Gleision Colliery mining accident in Cilybebyll after campaigning alongside the victims’ families for several years.

In the 2026 Senedd election, she was elected as a MS for the Brycheiniog Tawe Nedd constituency. She was later appointed Deputy First Minister and Cabinet Secretary for Social Justice in the ap Iorwerth government.

Personal life Sioned's husband, Daniel Gwydion Williams, is a professor of English Literature at Swansea University; he is also a writer and a semi-professional jazz musician. The couple live in Alltwen, Swansea Valley with their two teenage children.