Like many other Jewish comics, King worked the Catskill circuit known as the Borscht Belt. His career took off after appearances on "The Ed Sullivan Show", "The Perry Como Show" and "The Garry Moore Show". Living just outside New York City, King was frequently available when Ed Sullivan needed an act to fill in for a last-minute cancellation. King also became a regular guest host for "The Tonight Show Starring Johnny Carson", and he hosted the Oscars in 1972 and was the MC for President John F. Kennedy's inauguration in 1961. King was the long-standing host of the New York Friar's Club celebrity roasts and also served as the club's historian. He headlined two unsold television pilots on CBS, both titled "The Alan King Show". The first aired on September 8, 1961; the second aired on July 12, 1986.