Owen’s theatrical writing includes his libretto for Rachel Portman’s oratorio, The Water Diviner’s Tale, which premiered at the Royal Albert Hall for the BBC Proms in 2007. Unicorns, almost, a one man play about the life and work of WWII poet Keith Douglas, was developed with Old Vic, New Voices. In Easter 2011 Owen wrote the script and novelisation (The Gospel of Us) for The Passion, National Theatre of Wales’ 72 hour site-specific production in Port Talbot starring and directed by Michael Sheen, The Observer described the production as ‘the theatrical event of the decade’. Owen’s short play The Fair & Tender was performed as part of the Bush Theatre’s 66 Books.

His verse drama Pink Mist, commissioned by BBC Radio 4 and published by Faber in June 2013, won the Hay Festival Poetry Medal and the Wales Book of the Year 2014. His play, created with wounded soldiers, The Two Worlds of Charlie F. premiered at the Theatre Royal Haymarket and toured the UK and Canada, winning the Amnesty International Freedom of Expression Award at the Edinburgh Festival. Mametz was co-commissioned by National Theatre Wales and 14-18 NOW, WW1 Centenary Art Commissions,