Robin McLaurim Williams (born July 21, 1951) is an American TV, stage and film actor and comedian who has won an Academy Award for his performance in Good Will Hunting, as well as six Golden Globes, two Screen Actors Guild Awards and three Grammy Awards. His film career began in 1980 following his success in the television series Mork & Mindy, and he remains active as a film actor and stand-up comedian. He was voted 13th on Comedy Central Presents: 100 Greatest Stand-Ups of All Time.

In 1973, Williams was one of only 20 students accepted into the freshman class at Juilliard. Even more impressively, Williams, along with Christopher Reeve, were the only students accepted by John Houseman into the Advanced Program at the school that year. Reeve and Williams had several classes together in which they were the only two students. In their dialects class, Williams had no trouble mastering all dialects quickly, whereas Reeve was more meticulous about it. Williams's manic comedy did not impress all of his teachers, but his dramatic performances impressed everyone. Williams and Reeve developed a close friendship, and they remained good friends for the rest of Reeve's life. Williams visited Reeve after the horseback riding accident that paralyzed him from the neck down and cheered him up by pretending to be an eccentric Russian doctor (similar to his role in Nine Months). Williams claimed that he was there to perform a colonoscopy. Reeve stated that he laughed for the first time since the accident and knew that life was going to be okay.

After appearing in the cast of the short-lived The Richard Pryor Show on NBC, he was cast by Garry Marshall as the alien Mork in a guest role in the TV series Happy Days.

As Mork, Williams improvised much of his dialogue and devised plenty of rapid-fire verbal and physical comedy, speaking in a high, nasal voice. Mork's appearance was so popular with viewers that it led to a spin-off hit television sitcom, Mork and Mindy, which ran from 1978 to 1982. Williams became an overnight sensation, and Mork was featured on posters, coloring books, lunchboxes, and other merchandise.

Starting in the late 1970s and throughout the 1980s, Williams began to reach a wider audience with his standup comedy, including three HBO comedy specials, Off The Wall (1978), An Evening with Robin Williams (1982), and Robin Williams: Live at the Met (1986). His standup work has been a consistent thread through his career, as is seen by the success of his one-man show (and subsequent DVD) Robin Williams Live on Broadway (2002). He was voted 13th on Comedy Central's list "100 Greatest Stand-ups of All Time" in 2004.

After some encouragement from his friend Whoopi Goldberg, he was set to make a guest appearance in the 1991 Star Trek: The Next Generation episode, "A Matter of Time", but he had to cancel due to a scheduling conflict; Matt Frewer took his place as a time-traveling con man, Professor Berlingoff Rasmussen.

Williams also appeared on an episode of Whose Line Is It Anyway? (Season 3, Episode 9: November 16, 2000). During a game of "Scenes from a Hat", the scene "What Robin Williams is thinking right now" was drawn, and Williams stated "I have a career. What the hell am I doing here?"