Oscar the Grouch is a Muppet character on the television program Sesame Street.

Oscar has a green body (during the 1969-1970 season he was orange), has no nose, and lives in a garbage can. His favorite thing in life is trash; evidence for this is the song "I Love Trash". Although "The Grouch" aptly describes his misanthropic interaction with the other characters, it is also the name of his species.

Oscar can also become mobile with the help of his friend Bruno, the trashman, who carried Oscar around in his can. Bruno was a full-body costume which allows Oscar's puppeteer to manipulate Oscar while remaining hidden by the Bruno costume. (While Bruno was seen fairly regularly in Sesame Streets early days, he hasn't appeared on the show in over a decade.) Also, as seen in the Elmo's World episode 'Dance', the underside of his trash can is somewhat detachable, with Oscar's legs protruding from the bottom of his trash can. Other evidence of this can be seen in Christmas Eve on Sesame Street (1978), when Oscar is ice skating. For several seasons, Oscar was frequently shown with his friend and pet Slimey, an orange worm. On occasional episodes he has mentioned leaving Sesame Street to attend "the annual Grouch convention in Syracuse, New York".

Oscar is performed by Muppeteer Carroll Spinney. Spinney's other lead character is Big Bird. During the first season of Sesame Street, the street set was arranged such that Spinney, who is right-handed, was forced to operate Oscar's head with his left hand. A subsequent redesign of the set allowed him to switch hands. Spinney has said in interviews that he modeled Oscar's voice on that of a grumpy New York cab driver he once hailed.