Abbott and Costello (William "Bud" Abbott, 1895-1974, and Lou Costello, 1906-1959) were an American comedy team best known for their baseball-themed, wordplay comedy routine, "Who's on First?" The pair achieved success on stage (both burlesque and vaudeville), followed by their first national fame on radio (where their verbal routines were particularly well-suited), in film, and television. They were especially popular from the start of their movie career with Universal in 1940 until their partnership ended in 1956.
As with other teams, such as Laurel and Hardy, there was a physical contrast between tall straight man Abbott and the shorter, fatter Costello. Abbott (as straight man) was the sarcastic adult of the pair (a frustrated voice of reason on radio, while in movies and TV he often took a more domineering, conniving edge), while Costello was the child-like comic, the apparently innocent bumbler (but with an impish streak) who would shout excitedly (and in a drawn out manner) "HEY, ABBOTT!"
- "Just Because" from The Muppet Alphabet Album uses the concept of the "Who's on First?" skit as an increasingly frustrated Grover asks questions only to be told Y.
- On Sesame Street, Ernie's breathy gasps as he relates to Bert, "the staaa, the staaa-tue", in a sketch where the duo travel to Egypt, is inspired by Costello's frightened reaction in Abbott and Costello Meet Frankenstein and other films.
- In episode 422 of The Muppet Show, during the Veterinarian's Hospital sketch with a bunny as a patient, after a joke about Doctor Who, Nurse Janice says "Doctor Who's on first." Nurse Piggy comments that all she gets is Abbott and Costello instead of the patient's name. When the bunny joins in (saying he's not The White Rabbit, he's the Wrong Rabbit), Piggy gripes that it's now "Rabbit and Costello".
- In The Muppets Go Hollywood, Dick van Dyke catches Fozzie Bear in front of Grauman's Chinese Theatre with a bag of cement, planning to add his own signature in the cement next to Abbott and Costello, the Marx Brothers and the Ritz Brothers.
- Footage of Abbott and Costello Meet Frankenstein (1948) appears in the Muppet Babies episode "Remote Control Cornballs," specifically scenes of Bela Lugosi
- Footage of Abbott and Costello themselves, from Africa Screams (1949), appears in the Muppet Babies episode "At the Movies." Baby Bean Bunny, trying to find Bambi, wanders into a theater screen playing the movie, a scene where Abbott and Costello are paddling a boat in the jungle. Costello discovers an alligator and, with an eggbeater, makes a quick getaway. Later in the same episode, Bean befriends the movie's gorilla suited simian (redubbed by Frank Welker).
- In a Sesame Street "Theater in the Park" sketch, Telly Monster (as Romeo) yells for Alphabet in the distinct stylings of Costello calling for Abbott.
- "Boogie Woogie Bugle Boy," from the Abbott and Costello film Buck Privates, is performed in the Dinosaurs episode "Nuts to War (part 2)."
- In The Wubbulous World of Dr. Seuss episode "Horton Has a Hit", the Fox in Socks and Mr. Knox star in their own TV variety show. One scene shows them performing a "Who's On First?" routine, but with the name "Cindy Lou Who."
- In a DXD video, Kermit and Fozzie share an exchange about Whatnots resulting in a similar word play present in Abbott and Costello's "Who's On First?" sketch. Toward the end, a frustrated Fozzie even breaks the flow to interject with "third base!"
- In part 4 of The Muppet Show Comic Book: Muppet Mash, Statler and Waldorf have a "Who's on First?"-style exchange, with Waldorf being confused about a Poob named Hugh.
- On February 4, 2011, Ernie tweeted, "Y’know Abbot & Costello? Not sure what it is, but there’s something so familiar about those two…"