Sion Daniel Young

Siôn Daniel Young is a Welsh stage, television, and film actor whose work spans classical theatre, contemporary drama, and screen performance. Born in Cardiff, he began performing at Welsh-language eisteddfodau before training professionally at the Royal Conservatoire of Scotland.

Young’s stage career includes his first professional role in Daf James’s Llwyth (Tribe), a landmark production as the first Welsh-language play about gay characters written by a queer playwright. He later appeared at the National Theatre in War Horse and went on to play the lead role of Christopher Boone in the West End production of The Curious Incident of the Dog in the Night-Time at the Gielgud Theatre. His theatre work also includes the world premiere of Barney Norris’s Nightfall at the Bridge Theatre.

On screen, Young has appeared in film and television projects including Private Peaceful, Our World War, Keeping Faith, Hinterland, Witness Number 3, and the Apple TV+ series Slow Horses. He received significant recognition for his lead performance in the television film The Left Behind, earning a BAFTA Cymru nomination for Best Actor, with the film winning both BAFTA and Royal Television Society awards for Best Single Drama. In 2021, he portrayed Colin Stagg in Channel 4’s Deceit, depicting one of the most notorious miscarriages of justice in British legal history.

In 2024, Young starred in the BBC One drama Lost Boys and Fairies, the broadcaster’s first primetime gay adoption drama, written by Daf James. His performance earned him the BAFTA Cymru Award for Best Actor in 2025. He has since appeared in the Cardiff-set BBC One series The Guest, continuing a career defined by range, depth, and a strong connection to contemporary British and Welsh storytelling.