Llanelli is a constituency of the House of Commons of the Parliament of the United Kingdom. From 1918 to 1970 the official spelling of the constituency name was Llanelly. It elects one Member of Parliament (MP) by the first past the post system of election. Since 2005, it is currently represented by Nia Griffith of the Labour Party.

Dame Nia Rhiannon Griffith is a Welsh politician who has served as Member of Parliament (MP) for Llanelli since 2005. A member of the Labour Party, she has served as Shadow Minister for the Cabinet Office since 2023. She previously served as Shadow Minister for Exports from 2021 to 2023, Shadow Secretary of State for Defence from 2016 to 2020, and Shadow Secretary of State for Wales from 2015 to 2016 and 2020 to 2021.