I had my training on the stage, where I did a variety of roles. That's the fun of being an actor: to meet the challenge of creating new characters. But Pa Kettle is always the same. He can do anything; there is no need to establish any motivation. There's no kick in doing him over and over again. I have had dozens of offers to do television series, but I have turned them all down. I might do one-shot appearances; but I won't let myself get tied down to one character.
Kilbride began working in the theater at the age of 12 and eventually left to become an actor on Broadway. He first played an 18th-century French dandy in A Tale of Two Cities. His film debut was as Jakey in White Woman (1933), a Pre-Code film starring Carole Lombard. He left Broadway for good in 1942, when Jack Benny insisted that Kilbride reprise his Broadway role in the film version of George Washington Slept Here. According to Benny, Percy Kilbride was the same character offscreen and on: quiet and friendly but principled, refusing to be paid more or less than what he considered a fair salary. Kilbride followed up the Benny film with a featured role in the Olsen and Johnson comedy Crazy House (1943). In 1945, he appeared in The Southerner.
In 1947, he and Marjorie Main appeared in The Egg and I, starring Fred MacMurray and Claudette Colbert as a sophisticated couple taking on farm life. Main and Kilbride were featured as folksy neighbors Ma and Pa Kettle, and audience response prompted the popular Ma and Pa Kettle series. Pa Kettle became Kilbride's most famous role: the gentle-spirited Pa seldom raised his voice, and was always ready to help friends—by borrowing from "other" friends, or assigning any kind of labor to his Indian friends Geoduck and Crowbar.
Kilbride disliked making the Kettle films. In a 1953 interview, he discussed the monotony of his career due to his portrayal of Pa Kettle:
On September 21, 1964, Kilbride and another actor, Ralf Belmont, were struck by a car while crossing the street in Hollywood.
