Formally established in 1999, Friends of the San Francisco Public Library is the union of the Friends of the San Francisco Public Library and the Library Foundation of San Francisco. Although initially called Friends and Foundation, the organization is now called Friends of the San Francisco Public Library.      

Thirty-eight years earlier, in 1961, the original Friends was founded by Marjorie Stern, Mary Louise Stong, Hilde Kolb, and Grace Macduff Parker. Volunteers performed every task in the first few years including organizing book sales, processing membership contributions, staging special exhibits, and sponsoring citywide poetry contests.

Through the years, Friends soon began to play an active role as an advocacy organization for the Library. Those efforts culminated in 1988, when Friends realized their long time goal of a new Main Library by championing Proposition A, a bond issue that would fund $109.5 million to build a new Main Library. To help pay for costs not covered by the bond, the Library Foundation of San Francisco was established. After an extraordinary outpouring of more than 17,000 donations from the residents and organizations of San Francisco and beyond, the New Main Library opened its doors on April 18, 1996.

Friends continued efforts to create a superior, free public library by championing the Library Preservation Fund or Proposition E in 1994. Prop E established 15 years of funding by earmarking a percentage of City revenue for the Library. But there was still more work to do and in 2000, Friends (now merged with the Library Foundation) championed a $106 million bond measure to build and refurbish 24 neighborhood branch libraries city-wide. As with the Main, public bonds will not pay for equipment or furnishings inside the branches. To meet this need, Friends is charged with raising $16 million through the Neighborhood Library Campaign.