West Side Story is a musical conceived by Jerome Robbins with music by Leonard Bernstein, lyrics by Stephen Sondheim, and a book by Arthur Laurents.

Inspired by William Shakespeare's play Romeo and Juliet, the story is set in the mid-1950s in the Upper West Side of Manhattan in New York City, then a multiracial, blue-collar neighborhood. The musical explores the rivalry between the Jets and the Sharks, two teenage street gangs of different ethnic backgrounds. The members of the Sharks, from Puerto Rico, are taunted by the Jets, a white gang.[1] The young protagonist, Tony, a former member of the Jets and best friend of the gang's leader, Riff, falls in love with Maria, the sister of Bernardo, the leader of the Sharks. The dark theme, sophisticated music, extended dance scenes, and focus on social problems marked a turning point in musical theatre.

The original 1957 Broadway production, directed and choreographed by Robbins, marked Sondheim's Broadway debut. It ran for 732 performances before going on tour. The production was nominated for six Tony Awards, including Best Musical, in 1958, winning two.[2] The show had an even longer-running West End production, a number of revivals, and international productions. A 1961 musical film adaptation, co-directed by Robert Wise and Robbins, starred Natalie Wood and Richard Beymer. The film was nominated for eleven Academy Awards and won ten, including Best Picture. A 2021 film adaptation, directed by Steven Spielberg, starred Ansel Elgort and Rachel Zegler.