Knotts was recognized in 2000 with a star on the Hollywood Walk of Fame. He continued to act on stage, but much of his film and television work after 2000 was as voice talent. In 2002, he appeared again with Scooby-Doo in the video game "Scooby-Doo! Night of 100 Frights". (Knotts also spoofed his appearances on that show in various promotions for Cartoon Network and in a parody on "Robot Chicken", where he was teamed with Phyllis Diller.) In 2003, Knotts teamed up with Tim Conway again to provide voices for the direct-to-video children's series "Hermie and Friends", which continued until his death. In 2005, he was the voice of Mayor Turkey Lurkey in "Chicken Little" (2005), his first Disney movie since 1979. On September 12, 2003, Knotts was in Kansas City in a stage version of "On Golden Pond" when he received a call from John Ritter's family telling him that his former "Three's Company" co-star had died of an aortic dissection that day. Knotts and his co-stars attended the funeral four days later. Knotts had appeared with Ritter one final time in a cameo on "8 Simple Rules for Dating My Teenage Daughter". It was an episode that paid homage to their earlier television series. Knotts was the last "Three's Company" star to work with Ritter.