Maria is a passionate young Puerto Rican immigrant who has recently moved to New York City. She works alongside Anita in a bridal shop and is eager to transition into adulthood, feeling stifled by her family's protective rules. While she is initially obedient to her older brother, her sudden and intense romantic connection pushes her to defy neighborhood boundaries.

Tony is a sandy-haired young man who works at the local drugstore. As the former co-founder of the Jets, he has recently distanced himself from gang activities because he senses a major, positive shift approaching his life. He is an idealist who believes he can bridge the hostile divide in his community through sheer optimism.

Riff is the energetic and driven leader of the Jets. He views the gang as a surrogate family and demands lifelong loyalty from everyone involved. He attempts to impose order on street warfare through organized war councils, fully convinced that defending his gang's territory is a matter of vital honor.

Bernardo is the proud, handsome leader of the Sharks. He harbors deep, justified resentment toward the systemic prejudice his fellow Puerto Ricans face in America. He actively rejects attempts to assimilate into a society that treats him poorly, choosing instead to consolidate power and pride within his own community.

Anita is an observant, sharp-witted Puerto Rican woman who embraces life in the United States. She is engaged to Bernardo and acts as an older, more experienced sister figure to Maria. She understands the harsh realities of gang tension but prefers to focus on dancing, socializing, and her romantic life.

Chino is a gentle, sweet-faced boy who belongs to the Sharks. He is polite, relatively timid, and follows Bernardo's directions closely. He serves as the family's chosen suitor for Maria, though he lacks the boldness that Maria secretly desires in a partner.

Doc is a middle-aged man who has run the local drugstore for twenty-seven years. He employs Tony and tolerates the Jets using his store as a hangout spot. He constantly attempts to impart wisdom and warn the teenagers about the destructive path of their gang violence.

Action is a catlike ball of fury and the most aggressive member of the Jets. He operates with a remarkably short fuse and is always ready for a physical confrontation. He deeply resents any form of authority or any adult who labels his group as juvenile delinquents.

A-rab is an explosive little ferret of a teenager who treats the gang lifestyle as a chaotic game. He struggles to understand the actual severity of the violence surrounding him, preferring to mock authority figures and tag along with the older boys.

Baby John is the youngest member of the Jets. He is constantly awed by his inclusion in the gang and tries his hardest to project a tough, mature exterior, despite clearly being unequipped for the brutal realities of street warfare.

Anybodys is a scrawny teenage tomboy dressed in a pathetic imitation of the Jets' attire. She desperately wants to be accepted as an official member of the gang, constantly lingering on the periphery despite enduring heavy teasing and repeated dismissals from the boys.

Lieutenant Schrank is a plainclothes detective tasked with keeping order in the neighborhood. He uses a charming, authoritative manner to mask his deep-seated bigotry. He actively attempts to manipulate the Jets into doing his dirty work, showing blatant favoritism in his policing.

Sergeant Krupke is a large, goon-like beat cop who serves alongside Lieutenant Schrank. He represents the blunt physical force of the law in the neighborhood and is frequently the target of the Jets' mockery and evasion tactics.

Glad Hand is an overly cheerful, square social worker of about thirty. He attempts to foster peace and community integration through structured social activities, totally failing to grasp the deadly seriousness of the teenagers' hatred for one another.

Big Deal is a bespectacled member of the Jets who styles himself as an expert on gang rules and street protocol. He stands behind Riff and participates in the gang's strategic planning sessions.

Velma is a young, sexy teenager fully immersed in the jive culture of the Jets. As Riff's girlfriend, she holds a prominent social spot among the Jet girls and enthusiastically supports the gang's rivalry against the Sharks.

Rosalia is a quietly dressed Shark girl who frequently expresses a nostalgic longing to return to Puerto Rico. Her sentimental views on her homeland provide a sharp contrast to the other girls who prefer their new lives in New York.