An Associate of Theatr Clwyd, Sion was born and raised in Gwynedd and trained at the Royal Welsh College of Music and Drama.
Theatre credits include: Hamlet, Last Christmas (Theatr Clwyd/Dirty Protest) – a one-man show nominated for Best Production at the TCW Awards and performed in Wales, at the Edinburgh Fringe Festival and the Soho Theatre, London, Cyrano De Bergerac, Hamlet, Copenhagen, Rape of the Fair Country, Glengarry Glen Ross, Bruised, As You Like It, Taking Steps, Roots, The Taming of the Shrew, A Small Family Business, A History of Falling Things, Write to Rock, A Midsummer Night’s Dream, The Way It Was, The Druid’s Rest, Hobson’s Choice (Theatr Clwyd), Crazy Gary’s Mobile Disco (Waking Exploits), Silly Kings (National Theatre Wales), Y Storm, Bobi A Sami (Theatr Genedlaethol Cymru), Muscle (Hull Truck Theatre), Muscle (Bristol Old Vic), Blink (FAB Theatre/Brits Off Broadway Festival, 59E59 Theaters, New York), Porth y Byddar (Theatr Clwyd /Theatr Genedlaethol Cymru), Fuddy Meers (Scamp/Arts Theatre), Y Byd A’i Brawd (RWCMD/Sgript Cymru), Indian Country (Sgript Cymru), Woyzeck (ELAN Wales).
His film and TV credits include: Dim ond y Gwir (S4C), Tir, Ysbyty Hospital, The Indian Doctor, Ddoe Am Ddeg, Phoneshop, series 1 & 2 (E4), Tati’s Hotel, Pen Talar, Caerdydd, Ar y Tracs, Ar y Tracs 2, Me and Mary Jane, Cowbois ac Injans , Talcen Caled, Casualty, Treflan, The Good Catch, Pen Tennyn.
Extensive radio work for BBC Radio and BBC Radio Wales.
Awards: the Spotlight Prize 2004, the James Westaway Award 2003.