Mostyn trained at Mountview Theatre School and graduated with a BA (hons) in Performance.
Recent theatre work includes: Perkins in Seven Brides for Seven Brothers, Theatre Royal Haymarket, London; Bobby in Cabaret, English Theatre Frankfurt; ensemble in South Pacific, Symphony Hall Birmingham; Sammy in Blood Brothers, Phoenix Theatre London; Avrahm in Fiddler on the Roof, national tour; Gaveston in Edward II, Oval, London; Annas in Jesus Christ Superstar, English Theatre Frankfurt; Caleb in Seven Brides for Seven Brothers, national tour; Dromio of Ephesus in The Comedy of Errors, national tour; Viceroy inNaked Flesh, Arts Theatre, Brighton; Johnny in Circus Agogo, New End Theatre London; Goddard in Let Him Have Justice, Cochrane Theatre London and Charles inMe and My Girl, Devonshire Park Theatre Eastbourne. Television and recording work includes: Blackpool (BBC); South Pacific (BBC Radio 2); Let Him Have Justice (TER); A Decline of Magic (Wodum) and adverts for Pilsner and Honda.
