In 2011, Ben-Adir performed in Gillian Slovo's critically acclaimed sell-out play The Riots at the Tricycle Theatre
In 2012, he played Demetrius in A Midsummer Night's Dream at Regent's Park Open Air Theatre
In 2013, he played Borachio in Mark Rylance's production of Much Ado About Nothing at the Old Vic in London and also played in God's Property at the Soho Theatre.
