bbott and Costello (William (Bud) Abbott, 1897-1974; Louis Cristillo, 1906-1959) were an American comedy duo whose work in radio, film, and television made them one of the most popular and respected teams in comedy history. Their "Who's on First?" routine, developed during their years in burlesque, is widely considered to be one of the greatest comedy sketches of all time.

They received their first national exposure in 1938 when they appeared on radio's The Kate Smith Hour. Their popularity on the program grew and they stayed on as regulars for two years. This led to roles in a Broadway musical, "The Streets of Paris," in 1939. In 1940 they were signed by Universal for the film One Night in the Tropics. Cast strictly in a supporting capacity, they nonetheless stole the show with several classic routines, including their immortal "Who's on First?" Universal signed them to a long-term contract and their second film, "Buck Privates," 1941 secured their place as movie stars. The duo made over 30 films between 1940 and 1956 (see list below) and were among the most popular and highest-paid entertainers in the world during World War II. Among their most popular films are "Hold That Ghost," "Who Done It?", "Pardon My Sarong," "The Time of Their Lives," "Buck Privates Come Home," "Abbott and Costello Meet Frankenstein," and "Abbott and Costello Meet the Invisible Man."

The team also appeared on radio throughout the 1940s. They began by hosting a summer replacement series for Fred Allen on NBC in 1940, then joined Edgar Bergen and Charlie McCarthy on the Chase and Sanborn program in 1941. During the same period two of their films, "Buck Privates" and "Hold That Ghost," were adapted for radio and presented on Lux Radio Theater. On October 8, 1942 the team launched their own weekly show on NBC sponsored by Camel cigarettes. They moved to ABC (the former NBC Blue Network) from 1947-49.

By 1951, the twosome had moved to television--first as one of the rotating hosts of The Colgate Comedy Hour (Eddie Cantor and Bob Hope were among the others) and then, the following year, in their own situation comedy, The Abbott and Costello Show. The half-hour series was loosely adapted from their radio show, but cast the duo as unemployed wastrels. One of the show's running gags involved Abbott perpetually nagging Costello to get a job to pay their rent, while Abbott barely lifted a finger himself in that direction. The show featured Sidney Fields as their landlord and Hillary Brooke as a friendly neighbor who sometimes got involved in the pair's schemes. Another semi-regular was Joe Besser, who played Stinky, a 40-year-old sissy dressed in a Little Lord Fauntleroy suit. The Abbott and Costello Show ran from 1952 to 1954, but the show found a new life in syndicated rerun broadcast in the late 1960s and early-to-mid 1970s, and the episodes were probably seen by more viewers this time around than when the show was actually produced.