However, Allen's wit wasn't well-suited to vaudeville audiences, and after one unsuccessful performance, he quit the show.
Allen left vaudeville and went on to work in Shubert Brothers' theatrical productions such as The Passing Show in 1922. The show ran for ten weeks at Broadway's Winter Garden Theatre. In that show, he met one of the chorus girls, Portland Hoffa, whom he married.
He earned critical acclaim for his comedic work in several of the productions in which he appeared, particularly Vogues and Greenwich Village Follies. He also wrote a humor column for Variety called "Near Fun."
Fred Allen's first exposure to radio came when he and his wife performed on the Chicago radio show WLS Showboat. Later, the couple landed a spot on Arthur Hammerstein's musical show, Polly. The show also featured a young Cary Grant. Other programs he appeared on included The Little Show (1929-30) and Three's a Crowd (1930-31), and from that point on, he began to dedicate himself to radio full-time.
Good friends in real life, Fred Allen and Jack Benny unintentionally created a gag in 1937, in which each disputed with the other from his own program. The back-and-forth between them became so successful that both continued with it for a decade.
After their show ended, Allen became a regular guest on NBC's The Big Show (1950-1952), hosted by Tallulah Bankhead. He appeared on 24 of the show's 57 installments, including the inaugural, proving that he had not lost his trademark wit. In some respects, The Big Show was inspired by Allen's old show: former Texaco Star Theater host Jimmy Wallington was one of The Big Show's hosts, and Portland Hoffa also made several appearances.
Allen attempted three television projects that were short-lived, including an adaptation of "Allen's Alley" to the new medium. The other two were game shows. One of them, Judge For Yourself (subtitled "The Fred Allen Show") was a game show that incorporated musical numbers.
Allen also worked in his later years as a newspaper columnist and humorist. He wrote Treadmill to Oblivion (in 1954, recalling his years in radio and television) and Much Ado About Me (in 1956, about his childhood and his years in vaudeville and Broadway). The first of the books was one of the best sellers about the classic radio era. But before finishing the last chapter of the second, Allen suffered an acute myocardial infarction that caused his death at the age of 61. His death occurred in New York City. Allen is buried at Gate of Heaven Cemetery in Hawthorne.
Fred Allen has two stars on the Hollywood Walk of Fame: one for his radio work at 6709 Hollywood Boulevard. And another for his television work at 7021 Hollywood Boulevard.