Silk's career as a voice actor began in 1999, starting with the video game Gex 3: Deep Cover Gecko and at the same time providing voice to Aks Moe (played by a different actor, Mark Coulier). Silk voices the lines supporting the Senator of the Trade Federation Lott Dod for a commission to investigate Queen Amidala's accusations during the Naboo Crisis.
Silk recorded his lines for The Phantom Menace at Abbey Road Studios in London with George Lucas instructing him what the characters look like, feel like and sound like.
For the next few years, Silk appeared in different video games, including MediEvil II, Hogs of War, Gladiator: Sword of Vengeance, Battalion Wars, Black & White and Dragon Quest VIII. He usually plays various characters in each of his works.
Since 2005, Silk has also acted in TV series such as Fifi and the Flowertots (credited as Mark Silk), Legend of the Dragon, Bob the Builder, Roary the Racing Car and Danger Mouse.