Fell was born on March 24, 1924 in Philadelphia, Pennsylvania, to Samuel and Edna Feld. His father was an Austrian Jewish immigrant, and his maternal grandparents were Russian Jews. Samuel was a restaurateur and the family lived at 416 South 4th Street. He attended Central High School of Philadelphia. He studied drama at Temple University after serving as a tail gunner on a B-25 Mitchell in the United States Army Air Forces during World War II. He later honed his craft at The Actors Studio and the Black Hills Players.

On May 21, 1950, Fell married Dolores Pikoos in Philadelphia. They divorced in 1954 and Fell married and divorced two subsequent times. He had two daughters, Tracy and Mara, with his second wife and adopted a son with his third wife, Karen Weingard.

From 1977 to 1979, Fell portrayed the main characters’ hardnosed landlord Stanley Roper on the hit sitcom Three’s Company (a role with some similarities to Mr. McCleery in The Graduate). He continued the role as the co-lead with Audra Lindley playing his wife, Helen, on The Ropers, a spin-off which lasted two seasons.

Fell won a Golden Globe Award for Best TV Actor in a Supporting Role in 1979 for Three’s Company. He was nominated for an Emmy Award for his dramatic performance as the boxing trainer of Tom Jordache (Nick Nolte) in the miniseries Rich Man, Poor Man. His final television appearance was a cameo as Mr. Roper on an episode of the sitcom Ellen in 1997.

Aside from Fell’s best-known television work, he also played minor character roles in several films, including the original Ocean’s 11, It’s a Mad, Mad, Mad, Mad World, PT 109, The Graduate, Bullitt and Catch-22 (as Sergeant Towser). He appeared alongside Ronald Reagan in Reagan’s last film, The Killers. In 1992, he starred as a Hotel owner in a comedy movie called Hexed.

On November 26 (Thanksgiving Day) of 1998, Fell had become too weak to get out of bed at his Marina del Rey home. He was rushed to the hospital where he was diagnosed with bone marrow cancer. He died at the Motion Picture and Television’s retirement home in Woodland Hills, California on December 14, 1998 at the age of 74. He was interred at Mount Sinai Memorial Park Cemetery.