Pee-wee Herman is a comedy character created and portrayed by the American comedian Paul Reubens. He starred in films and television series during the 1980s. The childlike Pee-wee Herman character developed as a stage act that quickly led to an HBO special in 1981. As the stage performance gained further popularity, Reubens took the character to motion picture with Pee-wee's Big Adventure in 1985, toning down the adult innuendo for the appeal of children. This paved the way for Pee-wee's Playhouse, an Emmy Award-winning children's series that ran on CBS from 1986 to 1991. Another film, Big Top Pee-wee, was released in 1988.

Because of negative media attention following a scandal in 1991, Reubens decided to shelve his alter ego during the 1990s, but gradually resurrected it during the following decade. It was at that time that Reubens addressed plans to write a new Pee-wee film, Pee-wee's Playhouse: The Movie. In June 2007, Reubens appeared as Pee-wee Herman at the Spike TV's Guys' Choice Awards for the first time on television since 1992. After a lengthy hiatus, a third film, Pee-wee's Big Holiday, was released by Netflix in 2016 and was the last time Reubens portrayed the character before his death in 2023.

In the 1970s, Reubens joined the Los Angeles–based improvisational comedy team the Groundlings and remained a member for six years, working with Bob McClurg, John Paragon, Susan Barnes and Phil Hartman. Hartman and Reubens became close friends, often writing and working on material together. Reubens wrote sketches, developed his improvisational skills and, with Hartman, he developed the Pee-wee Herman character.

In 1977, The Groundlings staged a performance in which its members created characters one might see in a comedy club. Reubens decided to play a guy that everyone immediately knew would never make it as a comic, partly because Reubens could not remember jokes in real life – he had trouble remembering punch lines and could not properly piece information in sequential order. Pee-wee Herman was born that night, his distinctive guttural "Ha Ha", followed by a low, "Heh Heh Heh" laugh became the character's catch phrase, as did his insult comeback, "I know you are, but what am I?"

Pee-wee Herman's signature gray glen plaid suit was originally a custom-made suit that Reubens had borrowed from the Groundlings director, Gary Austin; the small red bow tie was given to him by an acquaintance. Pee-wee's later checkered clothing and persona were largely lifted from manic 1950s children's TV host Pinky Lee. Also incorporated into the look were short black hair, pale skin with red rouge and red lipstick.

The inspiration for the name came from a Pee-wee brand miniature harmonica and the surname of an energetic boy Reubens knew from his youth. Reubens thought the name Pee-wee Herman was a name that sounded too real to be made up, and like a real name a parent would give a child that they didn't really care about.

Sometime in 1979, Reubens debuted his character on the television show The Dating Game, appearing three times.

Throughout his film and television programs, Pee-wee Herman's background has remained relatively ambiguous. During interviews, he has been portrayed as though he is a real life stand-up comedian who expanded his career by playing himself in his films and TV series. This is echoed by the fact that a star on the Hollywood Walk of Fame was awarded to Pee-wee Herman rather than Paul Reubens.