Bamber was born in Hammersmith, London to Northern Irish mother Elizabeth (Liz) and an American father Ralph. He holds American citizenship through birth.[1] Bamber was educated at the independent St Paul's School in Barnes, London, and received a first class honours degree in Modern Languages (Italian and French) at St John's College, Cambridge, before attending the London Academy of Music and Dramatic Art (LAMDA).

In 2003, Bamber starred as Lee 'Apollo' Adama, a Captain in the Colonial Fleet, in Ron Moore's re-make Battlestar Galactica. This miniseries effectively served as pilot for a potential TV show. A TV series was commissioned in a collaborative effort between the Sci Fi Channel (United States) and Sky TV (the British broadcaster). Battlestar Galactica is filmed mostly in Vancouver, British Columbia and as of mid 2008, is currently in its fourth and final season.

In the role of Lee Adama, Bamber notably speaks with an American accent. He also has darkened hair, in an effort to more closely resemble Edward James Olmos, who plays his character's father.

Bamber married actress Kerry Norton in September 2003, and they have three daughters: Isla Elizabeth Angela Griffith, and twins Darcy and Ava.

Norton has made several appearances as Paramedic Layne Ishay in Battlestar Galactica. (Unlike Bamber, her character retains her native English, specifically Received Pronunciation, accent.)

He has 5 brothers and a sister, Anastasia Griffith, who is an actress.