Abbott was born into a circus family, and he managed burlesque houses before he met Costello. He spent much time backstage studying the top American comics of the day, including W.C. Fields (Fields, W.C.), Bert Lahr, and the comedy team of Bobby Clark and Paul McCullough. In 1923 Abbott produced his own show, Broadway Flashes, in which he played a leading role in order to save the cost of an actor's salary. He spent the next decade perfecting his talents as a straight man and working with a number of partners that included his wife, Betty.

As a young man, Costello greatly admired Charlie Chaplin (Chaplin, Charlie). In 1927 he moved to Hollywood where he worked as a stuntman; after an injury, he quit stunt work to perform in New York burlesque. Although he had never worked on stage before, he quickly became one of the top burlesque comics and learned the hundreds of standard comedy routines of the circuit. These stock routines allowed for comics to work interchangeably with a variety of partners (often on a moment's notice); in such informal pairings, Abbott and Costello performed together sporadically throughout the early 1930s, before their official teaming in early 1936.

During the next few years the team worked the burlesque circuit and perfected routines each had done countless times with other partners, including the baseball sketch “Who's on First?” for which they became famous. Although they would occasionally vary their standard formula in a few of their films, Abbott and Costello's act remained mostly consistent throughout their two decades as a team. Abbott was something of a bully and a schemer, and Costello played the hapless, childlike patsy who was known for catchphrases such as “I'm a ba-a-a-a-d boy!” Their characters were stock types of the burlesque tradition; as such, their comedy relied more on the rapid-fire delivery of gags than on character or situational humour. They have been credited as one of the few comedy teams to have preserved on film many of the classic routines of the American vaudeville and burlesque traditions.

When Abbott and Costello's box-office status began to slip during the early 1950s, they found renewed popularity on television, both as recurring hosts of The Colgate Comedy Hour (1950–55) and as stars of The Abbott and Costello Show (1952–54). After their final film, Dance with Me, Henry (1956), Abbott and Costello went their separate ways. Costello reprised some of the old routines for The Steve Allen Show, and he appeared in the comedy film The 30 Foot Bride of Candy Rock (1959). Abbott appeared in a dramatic role for television's GE Theater in 1961, teamed with comic Candy Candido for some personal appearances in the early 1960s, and provided his own voice for an Abbott and Costello cartoon series in 1967.