hell-o!

Johnson began acting at the age of 6, performing as the son of Macduff alongside Rufus Sewell’s Macbeth in 1999, and inArthur Miller’s All My Sons in 2000. His TV roles have included his turn as Niker in the BBC's 2004 adaptation of the novel Feather Boy, Aaron in Danny Brocklehurst's TV serial Talk to Me, and Owen Stephens in Nearly Famous. In 2003, Johnson appeared as a young Charlie Chaplin in Shanghai Knights. In 2006, Johnson appeared in The Illusionist, appearing in the flashback scenes in the beginning of the film as Edward Norton's character as a teenager, Eduard Abramovicz. The scenes show the young Eduard as he first learns magic, and to do this, Johnson himself learned how to perform the ball trick displayed by his character. He also learned how to perform the balancing of the egg on the stick, although that was effected mechanically.Johnson subsequently appeared as the heartthrob, Robbie, in the 2008 teen comedy Angus, Thongs and Perfect Snogging, Lorimer Black in Armadillo, and Prosper in The Thief Lord.

Johnson appeared as John Lennon in the 2009 biopic Nowhere Boy, directed by Sam Taylor-Wood. In 2010, Johnson appeared as Dave Lizewski, the lead character inMatthew Vaughn and Jane Goldman's film Kick-Ass, based on the superhero comic book of the same name by Mark Millar,and has appeared as the central character "William" in Hideo Nakata's Chatroom.

In December 2010, Johnson joined the cast of Albert Nobbs as a replacement for Orlando Bloom, who dropped out of the production due to his wife's pregnancy.Johnson starred in R.E.M.'s 2011 music video Überlin which was also directed by his then-fiancée.