Fay McKenzie, an actress and singer whose film career spanned a century and crested when she was Gene Autry’s leading lady in five early 1940s horse operas, died on April 16 in Highland Park, Calif. She was 101.

Her death was confirmed by Bryan Cooper, a distant relative.

Ms. McKenzie made her screen debut in 1918, when she was 10 weeks old, cradled in Gloria Swanson’s arms in “Station Content,” a five-reel silent romance. Her last role was a cameo appearance with her son, Tom Waldman Jr., in “Kill a Better Mousetrap,” a comedy, based on a play by Scott K. Ratner, that was filmed last summer and has yet to be released.

In between, she appeared in five movies for the director Blake Edwards (in one instance playing the hostess of the title bacchanal in “The Party,” a 1968 madcap comedy written by her husband, Tom Waldman, and starring Peter Sellers); co-starred with Don Barry in “Remember Pearl Harbor” in 1942; and was cast in dozens of B-movies, revues and Broadway productions.

Despite her precocious start in motion pictures, by her account she was discovered, in the Hollywood vernacular, only in 1941, when Herbert J. Yates, the president of Republic Pictures, spotted her in a bathing suit poolside at the home of her brother-in-law Billy Gilbert, the comedian renowned for his spasmodic sneezes.