Bamber has worked on many British television series, mini-series and TV movies. He appeared in the BBC adaptations of Hanif Kureishi's The Buddha of Suburbia, and Jane Austen's Pride and Prejudice, in which he portrayed the Bennets' clergyman cousin, Mr. Collins. He also played the part of a junior treasury minister and Stamp enthusiast, Julian Whitaker, in an episode of The New Statesman, in which Alan frames Whitaker and forces his resignation. In 1997 he starred as Eric Slatt in two series of Steven Moffat's Chalk, contributing to the audio commentaries for the DVD release in 2008. His best known international television role to date was his 2005–2007 role as Marcus Tullius Cicero in the HBO/BBC2 original television series, Rome. In Poirot Series 3: Episode 7 "The Double Clue," he plays the effete middleman to a jewellery collector who is robbed. Bamber also played Adolf Hitler in Bryan Singer's film, Valkyrie.