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

Oscar has a green body, and lives in a trash can. His favorite thing in life is trash; evidence for this include the fact that he has never been shown outside his trash can on a single episode, and the song "I Love Trash". He's known as "The Grouch" because of his typically grouchy moods, which tend to be on the whiney side, although he can also be very clever. Also, he is of the grouch species. Some say he is very smart.

Oscar inspired an Apple Macintosh hack written by Eric Shapiro and shown at the 1989 MacHack conference, featuring a singing animated Oscar that appeared from the trash can whenever a file was thrown away. The hack was so popular that some parents lost the entire contents of their hard disks to preschoolers wanting to see more of Oscar. (Late Nights with MacHack, p. 27)