David Ketchum (b. 1928) is an actor, writer, and voice artist, best known for his recurring role on Get Smart as the disgruntled Agent 13, perpetually staked out inside of pots and furniture. Ketchum appeared in "The Man from Alphabet" sketch, seen in the first Sesame Street test show, as a home owner in a Napoleon hat whose newspaper is stolen by Dunce.
Ketchum had previously worked with fellow "Man from Alphabet" actors Gary Owens, Jim Thurman, and Gene Moss, on the animated series Roger Ramjet, as the narrator, and again on the comedy album The Funny Side of Bonnie and Clyde (as Clyde Barrow). Ketchum was also a regular on the sitcoms I'm Dickens, He's Fenster (as Mel Warshaw) and Camp Runnamuck (as Spiffy), and made guest appearances on The Andy Griffith Show, Happy Days, The Munsters, The Mod Squad, and Green Acres.
Film credits include Love at First Bite (with George Hamilton and Arte Johnson) and The North Avenue Irregulars (with Cloris Leachman). Ketchum also scripted episodes of such series as The Love Boat, Wonder Woman, M*A*S*H, The Bionic Woman, and Full House.