The city of South Gate was incorporated in 1923 with a population of about 2,500 residents. The first South Gate Library was opened that same year in a back room of City Hall. Starting in 1931, the County of Los Angeles Free Library began providing library service to local residents.

In 1948, the County of Los Angeles built a library in the South Gate Civic Center, north of California Avenue and Firestone Boulevard. In the 1960's, plans were made to build a larger, more modern public library for the prospering community that was home to several major manufacturers, including General Motors.

In 1973, the Leland R. Weaver Library, named in honor of a former South Gate councilman, was officially opened to the public at its present location on Tweedy Boulevard.