"Lisa the Vegetarian" is the fifth episode of The Simpsons' seventh season. It originally aired on the Fox network in the United States on October 15, 1995. In the episode, Lisa decides to stop eating meat after bonding with a lamb at a petting zoo. Her schoolmates and family members ridicule her for her beliefs, but with the help of Apu, Paul McCartney, and Linda McCartney, she commits to vegetarianism.
Directed by Mark Kirkland, "Lisa the Vegetarian" is the first full-length episode David S. Cohen wrote for The Simpsons. David Mirkin, the show runner at the time, supported the episode in part because he had just become a vegetarian himself. Former Beatle Paul McCartney and his then wife Linda McCartney guest star in the episode. Paul McCartney's condition for appearing was that Lisa would remain a vegetarian for the rest of the series. The episode makes several references to his musical career, and his song "Maybe I'm Amazed" plays during the closing credits. "Lisa the Vegetarian" finished 47th in the ratings for the week of October 9–15, 1995, with a 9.0 Nielsen rating. It was the fourth highest-rated show on the Fox network that week. The episode received generally positive reviews from television critics. It has won two awards, an Environmental Media Award and a Genesis Award, for highlighting environmental and animal issues.