Soller acted in various plays following his graduation from RADA in 2008, and his breakthrough year came in 2011 where he starred in The Glass Menagerie at the Young Vic, The Government Inspector also at the Young Vic and in The Faith Machine at the Royal Court Theatre. Based on these performances he won the Evening Standard Theatre Award for Outstanding Newcomer.

In 2012 Soller starred in the West End hit A Long Day’s Journey into Night by Eugene O’Neill with David Suchet, Laurie Metcalf and Trevor White at the Apollo Theatre, and in the Roundabout Theatre Company’s production of Cyrano de Bergerac as Christian at the American Airlines Theatre in New York.

Soller appeared in BBC Three’s comedy Bad Education as the new teacher Mr Schwimer. In 2016 he appeared in BBC One’s Poldark, playing Ross’s cousin, Francis, and in The Hollow Crown, in the role of Clifford. He starred as an expert on apocalypses, Scotty, in Sky 1’s comedy drama You, Me and the Apocalypse. In 2015, he appeared as Gerald Croft in Helen Edmundson’s award-winning BBC adaptation of An Inspector Calls.