Born in Bury St. Edmunds, Suffolk, Maloney's first television appearance was as Peter Barkworth's teenage son in the 1979 drama series Telford's Change.

After the RSC, he went on to play in The Perfectionist at Hampstead, the title role of Peer Gynt for Cambridge Theatre Company, The London Cuckolds at the Lyric Hammersmith, Two Planks and a Passion by Anthony Minghella, directed by Danny Boyle at Greenwich and Built on Sand at the Royal Court.

He appeared on television[2] in Mr Wakefield's Crusade, on film as Mark in Truly, Madly, Deeply, and in 1994 he took the lead in the BBC adaptation of Love on a Branch Line.

He appeared in both the 1990 and 1996 film versions of Hamlet, as Rosencrantz and Laertes respectively,[3] and in several other Shakespeare screen adaptations, including the lead role in In the Bleak Midwinter by Kenneth Branagh.

2002 saw him play Brian Albumen, personal aide to Rik Mayall's Adonis Cnut character in the Gran and Marks penned TV sitcom Believe Nothing.

He played Cassius in the 2005 miniseries Empire, John Major in 2009's Margaret and Prime Minister Sir Robert Peel in the 2009 film The Young Victoria.