Kiera Marshall

Kiera Duncan Marshall (born ) is a Welsh Plaid Cymru politician who has served as a Member of the Senedd (MS) for Caerdydd Penarth since May 2026.

Raised in Townhill, Swansea, Marshall studied politics and economics, and worked as a researcher for Plaid Cymru in the Senedd. She unsuccessfully stood as a candidate for Cardiff West in the 2024 general election, and was elected to the Senedd in the 2026 election.

Early life and career Marshall was born in Her mother was a charity worker. Marshall attended Gower College Swansea, where she studied politics at A-level, and later studied economics at the London School of Economics. She has previously worked in hospitality and served as the deputy head of policy for the Welsh branch of the Federation of Small Businesses.

Political career Marshall had worked as the lead researcher for the Plaid Cymru Economy, Transport, and Post-16 Education group at the Senedd, The result was the second largest vote share increase (12.5%) for Plaid in the election and the party’s largest in a general election in Cardiff. She was elected alongside fellow Plaid members Anna Brychan and Leticia Gonzalez. Marshall had been placed second on the party candidates list for the constituency and had announced her candidacy on International Women's Day the same year. Marshall is a member of the Senedd Legislation Committee.

Electoral history

Personal life Marshall lives in Canton, Cardiff, with her partner and daughter. She was pregnant with their daughter during her candidacy in the 2026 election. She has learnt Welsh for over four years, not being taught as a child.

In 2021, Marshall was convicted of driving under the influence in Swansea City Centre on 8 May, receiving a £300 fine and being disqualified from driving for 17 months. The conviction resurfaced during her 2024 parliamentary candidacy, and she issued a statement saying that at the time of the incident she had been suffering from post-traumatic stress disorder due to being a victim of stalking.