Brocklebank has worked with the Royal Shakespeare Company in productions of "As You Like It" playing Silvius, Chiron in"Titus Andronicus", Rowland in "The Tamer Tamed" and Ralph in "Lord of the Flies". His other theatre credits include Martin Von Heilmann in "The Curse of the Werewolf" at the Union Theatre in London, John Rutherford in "Rutherford and Son" at the Royal Exchange in Manchester and John Honyman in "Cressida", directed by Nicholas Hytner for the Almeida Theatre in London's West End.