Russell is most known for his voice acting in the Thief game series as the protagonist Garrett. He also voiced Karras, chief antagonist of Thief II: The Metal Age, as well as voicing some of the minor characters in the series. Russell additionally contributed the voice of the starship Von Braun's central computer XERXES and that of William Bedford Diego in Irrational Games' System Shock 2. He has since become a popular figure in both communities.
Russell made his debut film appearances as Bob in the 2007 independent film Noëlle and as Luther Norris in the romantic comedy film Chatham released in 2008. He also played a minor role in the 2009 film The Ghosts of Girlfriends Past.