The San Diego free speech fight in San Diego, California, in 1912 was one of the most famous class conflicts over the free speech rights of labor unions. Starting out as one of several direct actions known as free speech fights carried out across North America by the Industrial Workers of the World, the catalyst of the San Diego free speech fight was the passing of Ordinance No. 4623 that banned all kinds of speech in an area that included "soapbox row" downtown. Clashes with the police in the area led to riots, multiple deaths including the deaths of police officers, as well as the retaliatory kidnapping and torture of notable Socialists, including Emma Goldman's manager Ben Reitman. As a direct result of the aftermath of this fight, the neighborhood of Stingaree was razed to the ground and the obliteration of San Diego's Chinatown.

San Diego is a city on the Pacific Ocean coast in Southern California located immediately adjacent to the Mexico–United States border. With a population of over 1.3 million residents, the city is the eighth-most populous in the United States and the second-most populous in the state of California after Los Angeles. The city is the seat of San Diego County, which has a population of nearly 3.3 million people as of 2021. San Diego is known for its mild year-round Mediterranean climate, extensive beaches and parks, its long association with the United States Navy, and its recent emergence as a healthcare and biotechnology development center.