Siân Gwenllian is a Welsh politician, who was elected to the National Assembly for Wales in the 2016 election. She represents the constituency of Arfon as a member of Plaid Cymru. Following the election, she was appointed Plaid Cymru’s spokesperson for Local Government, the Welsh Language, Equalities and Planning. She is currently a member of the Climate Change, Environment and Rural Affairs Committee and the Equality, Local Government and Communities Committee.
She previously served as a councillor on Gwynedd Council, representing Y Felinheli. Between 2010 and 2012 she was responsible for the authority's finance portfolio. Between 2012 and 2014 she was Cabinet Member for Education, lead on children and young people, and was deputy leader of the Council. In 2014, she was appointed Gwynedd Small Business Champion, responsible for promoting this sector of the economy in Gwynedd.
She was educated at Friars School, Bangor and at Aberystwyth and Cardiff universities. She was then a journalist with the BBC and HTV in Bangor before becoming a county councillor for Y Felinheli, the village where she was brought up.