Jonjo O’Neill (born 11 July 1978) is a Northern Irish actor known for his stage and television work.
O’Neill was born in Belfast. He trained at the Guildford School of Acting. His first television role was in Extremely Dangerous (1999).
A member of the Royal Shakespeare Company (RSC) 2009-2011 ensemble, his roles included Mercutio in Romeo and Juliet, Orlando in As You Like It, and Launcelot in Morte D’Arthur. His performances during the RSC’s six-week residency at Park Avenue Armory in New York were hailed as “forceful” and “irresistible.” At the 2012 World Shakespeare Festival in Stratford-upon-Avon, O’Neill played the title role in Roxana Silbert‘s production of Richard III at the Swan Theatre.
In 2012 he won praise for his performance in Lucy Prebble‘s play The Effect at the Royal National Theatre headlining alongside Billie Piper,  whom he later starred alongside in the 2013, fiftieth anniversary episode “The Day of the Doctor” of Doctor Who.