The Chicano Moratorium, formally known as the National Chicano Moratorium Committee Against The Vietnam War, was a movement of Chicano anti-war activists that built a broad-based coalition of Mexican-American groups to organize opposition to the Vietnam War. Led by activists from local colleges and members of the Brown Berets, a group with roots in the high school student movement that staged walkouts in 1968, the coalition peaked with a August 29, 1970 march in East Los Angeles that drew 30,000 demonstrators. The march was described by scholar Lorena Oropeza as "one of the largest assemblages of Mexican Americans ever." It was the largest anti-war action taken by any single ethnic group in the USA. It was second in size only to the massive U.S. immigration reform protests of 2006.

The event was reportedly watched by the Los Angeles FBI office, who later "refused to release the entire contents" of their documentation and activity. The Chicano Moratorium march in East L.A. was organized by Chicano activists Ramsés Noriega and Rosalio Muñoz. Muñoz was the leader of the Chicano Moratorium Committee until November 1970, when he was ousted by Eustacio (Frank) Martinez, a police informer and agent provocateur for the Alcohol, Tobacco and Firearms Enforcement Division (ATF) of the U.S. Treasury Department, who committed illegal acts to allow the police to raid the headquarters of the committee and make arrests. Muñoz had returned as co-chair of the Moratorium in February 1971.