He began his career as a standup comedian and then went on to appear in several films and sitcoms, including Rosemary's Baby; Beaches; All in the Family; Three's Company; Night Court; Wings; Ally McBeal; Everybody Loves Raymond; The Larry Sanders Show, in three episodes as Hank Kingsley's agent; Barney Miller in seven episodes, including in one as a man who propositions Detective Fish; Car 54, Where Are You?

; The Patty Duke Show; The Monkees; The Odd Couple; Happy Days; Friends; Roseanne, as Leon's co-worker and lover; Mad About You; The Dick Van Dyke Show, as Buddy Sorrell's pool shark brother; The Golden Girls; and Double Rush.

Other roles include appearing as a friendly spirit in the 1990 film Ghost, the episode "When I'm 64" of the TV series ALF as Jack, one of the residents of a retirement home.

[5] Leeds died of pneumonia on August 16, 1998, at Cedars-Sinai Medical Center in Los Angeles[1] at age 82.

"Happy Trails", an episode of Ally McBeal, featured footage of his prior appearances on the show, eulogizing his character.