The Peninsula Library System (PLS) is a consortium of 35 public and community college libraries working together to provide innovative and cost-effective service to their users. Founded in 1971, the system is a Joint Powers of Agreement and is funded primarily by member libraries: Burlingame Public Library, Daly City Public Library, Menlo Park Public Library, Redwood City Public Library, San Bruno Public Library, San Mateo County Libraries, San Mateo Public Library, South San Francisco Public Library, and the San Mateo County Community College District (including the College of San Mateo, Canada College and Skyline College). PLS also receives support from the state California Library Services Act funds, federal Library Services and Technology Act and local contracts for special services.

Thanks to PLS leadership and the cooperation of its members, residents of San Mateo County can borrow and return books at any local library. They can search a joint catalog of member library holdings and use other library services by logging on to plsinfo.org.