The Socialist Party of Oklahoma was a semi-autonomous affiliate of the Socialist Party of America located in the Southwestern state of Oklahoma. One of the last states admitted to the Union, the area later incorporated into Oklahoma had been previously used for reservations to which indigenous Native American populations were deported, with the area formally divided after 1890 into two entities — an "Oklahoma Territory" in the West and an "Indian Territory" in the East.

The Socialist Party of America (SPA) was a socialist political party in the United States formed in 1901 by a merger between the three-year-old Social Democratic Party of America and disaffected elements of the Socialist Labor Party of America who had split from the main organization in 1899.