Born in The Bronx, New York, Lionel Stander's career in film began in 1932. Strongly liberal and pro-labor, Stander was among the first group of Hollywood actors to be subpoenaed before the House Un-American Activities Committee in 1940, and he was the only one who appeared at that first round of hearings who was not cleared of the allegations that he was a Communist. Stander was subsequently fired from his studio, Republic Pictures, though he continued to work until being blacklisted when HUAC returned its attention to Hollywood in another series of hearings in 1947 and 1951. Stander then worked as a stock broker on Wall Street and as a journeyman stage actor, not returning to film until 1961.

Stander is perhaps best known for his supporting role on the 1979-1984 television series Hart to Hart (and a subsequent series of Hart to Hart made-for-TV movies) as "Max", the loyal butler, cook, and chauffeur to the wealthy, amateur detectives played by Robert Wagner and Stefanie Powers. However, he is also remembered for his role in Polanski's movie Cul de Sac and his small but convincing cameo in Sergio Leone's Once Upon a Time in the West, where he plays the bartender in the inn supposed to be in Monument Valley. In 1983, Stander won a Golden Globe Award for "Best Performance by an Actor in a Supporting Role in a Series, Mini-Series or Motion Picture Made for TV". In 1986, he became the voice of Kup in Transformers: The Movie.

Stander died of lung cancer in Los Angeles, California, at the age of 86. He is interred in the Forest Lawn Memorial Park Cemetery in Glendale, California.