Notable television roles include Jake Clampett (a deadbeat who mooches off the Clampetts) for two episodes of CBS's The Beverly Hillbillies, Blanche Morton's (Bea Benaderet's) brother Roger Baker on eight episodes of The George Burns and Gracie Allen Show, and Harvey Helm in a 17-episode stint on NBC's The Bob Cummings Show. Donovan also appeared in six episodes as Chris Norman of It's a Great Life, a sitcom with Frances Bavier, James Dunn and Michael O'Shea, which aired on NBC from 1954 to 1956. About this time, he also guest starred on Ray Bolger's ABC sitcom, Where's Raymond? and the NBC sitcom, The People's Choice, with Jackie Cooper. He also guest starred on the David Janssen crime drama, Richard Diamond, Private Detective. He played Mark Dawson in the 1959 Maverick episode "Maverick Springs". He was also in Wanted: Dead or Alive in the 1959 episode "Bad Gun" as the gun dealer Sheridan Appleby, in which he tries to recover a defective pistol that he had sold to an outlaw. He and Steve McQueen rescue a kidnapped senator's daughter when the faulty firearm explodes in the face of the bad guy.