The Zoot Suit Riots were a series of riots that took place June 3–8, 1943, in Los Angeles, California, United States, involving American servicemen stationed in Southern California and young Latino and Mexican American city residents. It was one of the dozen wartime industrial cities where race-related riots occurred during the summer of 1943, along with Mobile, Alabama; Beaumont, Texas; Detroit, Michigan; and New York City.

American servicemen and white Angelenos attacked and stripped children, teenagers, and youths who wore zoot suits, ostensibly because they considered the outfits, which were made from large amounts of fabric, to be unpatriotic during World War II. Rationing of fabrics and certain foods was required at the time for the war effort. While most of the white mobs targeted Mexican American youth, they also attacked African American and Filipino American young adults and children.

The Zoot Suit Riots followed the Sleepy Lagoon murder trial, after the death of José Díaz, a young Latino man in what was then an unincorporated commercial area near Los Angeles. Similar racist violence against Latinos happened in Chicago, San Diego, Oakland, Evansville, Philadelphia, and New York City as well. The defiance of zoot suiters became inspirational for Chicanos during the Chicano Movement.

California was a part of Mexico for 27 years, and part of the Viceroyalty of New Spain for centuries, before becoming part of the United States following the Mexican–American War. Because of this history, there has always been a large Latino population in California. During the early 20th century, many Mexicans immigrated for work to US border states that needed workers, areas such as Texas, Arizona, and California. They were recruited by farmers for work on the large farms and also worked in those states in non-agricultural jobs.

During the Great Depression, in the early 1930s, the United States deported between 500,000 and 2 million people of Mexican descent (including the expulsion of up to 1.2 million children who were U.S. citizens but accompanied their parents back to Mexico.) to Mexico (see Mexican Repatriation), in order to reduce demands on limited American economic resources. By the late 1930s, about three million Mexican Americans resided in the United States. Los Angeles had the highest concentration of ethnic Mexicans outside Mexico.

Job discrimination in Los Angeles forced minorities to work for below poverty level wages. The Los Angeles newspapers described Mexicans with racially inflammatory propaganda, suggesting a problem with juvenile delinquency. These factors caused much racial tension between Mexican immigrants, those of Mexican descent, and European Americans.

During this time, Los Angeles was undergoing an expansion, which caused disruptions in communal sites, family sites, and family patterns of social interactions due to poor city planning. One major decision was to put a million-dollar Naval training school for the Naval Reserve Armory in the Chavez Ravine, a primarily working-class and immigrant area for Mexican-Americans. As young Mexican-American men from the neighborhood grew agitated and began a campaign of harassment, intimidation, and resistance a year prior to the riots, the Chavez Ravine area would later be a hot spot for encounters between the zoot suiters and sailors.

Lalo Guerrero became known as the father of Chicano music, as young people adopted music, language, and dress of their own. Young men wore zoot suits—a flamboyant long jacket with baggy pegged pants, sometimes accessorized with a pork pie hat, a long watch chain, and thick-soled shoes. They called themselves pachucos. In the early 1940s, arrests of Mexican-American youths and negative stories in the Los Angeles Times fueled a perception that these pachuco gangs were delinquents who were a threat to the broader community.