Early in his career Risley was an animator on several television series including Attack of the Killer Tomatoes, Gladiators 2000 and the CBS Prime-time special "The Magic Paintbrush". Later he became a story artist for the Kids' Choice Awards-winning film The Rugrats Movie, then moved on to produce & direct the Emmy award-winning series Rugrats, the Emmy-nominated series The Wild Thornberrys, the Annie Award-nominated series Rocket Power, and the three-time Prime-time Emmy nominated series As Told By Ginger. In 2015 Mark produced & directed the TV series Yo-kai Watch.