In 2004, Bell was cast as John Kramer, known as Jigsaw, an engineer who wants others to appreciate the value of life via twisted "games", in the horror film Saw. The low-budget film was a box office success, spawning seven sequels: Saw II (2005), Saw III (2006), Saw IV (2007), Saw V (2008), Saw VI (2009), Saw 3D (2010), and Jigsaw (2017). He provided his voice for the Jigsaw character in the Saw video game (2009) and its sequel, Saw II: Flesh & Blood (2010), to which he provided his likeness. Even though Bell spent three weeks lying on a floor and had very few lines, his role was pivotal to the first film. For his role as "Jigsaw", Bell received MTV Movie Awards nominations in 2006 and 2007 for "Best Villain", won "Best Butcher" in the Fuse/Fangoria Chainsaw Awards and was given the "Best Villain in a Film Series" title at the 2010 Chiller-Eyegore Awards. Although he considers his role in Saw to have been "a great blessing", he hopes to soon have the opportunity to be cast against type. In 2016, he starred as hermit Yo Ling on the soap opera Days of Our Lives, revealed to be John Black's long lost father. He starred as the voices of the villain Doctor Alchemy and the malicious speed god and main antagonist Savitar on the third season of The Flash, in an uncredited role.