San Luis Obispo Carnegie Library, former Carnegie library and history museum in San Luis Obispo, California, United States

San Luis Obispo Carnegie Library is a Richardsonian Romanesque building designed by William H. Weeks. It has a tall hipped roof with two gabled wings, gargoyles in the gable ends, and an entrance portico with multiple round arches. The walls are mainly red brick with yellow sandstone trim, while the basement is faced in dark gray granite.

The San Luis Obispo Carnegie Library was funded by the Carnegie foundation in 1903 and built in 1905, taking over the city's subscription library program that had run since 1894. It served as a library until 1955 and became a county historical museum the following year. The building was listed on the National Register of Historic Places on March 30, 1995.

The building's name comes from Andrew Carnegie's foundation, which paid for its construction in 1903; it opened in 1905 as the city's subscription library, a service running since 1894. Since 1956 it has housed the county historical museum, now the History Center of San Luis Obispo County, with changing exhibits on local history and culture and a research room.

The building stands at 696 Monterey Street in downtown San Luis Obispo, within walking distance of Mission San Luis Obispo de Tolosa and the Dallidet Adobe and Gardens. The History Center occupies the former library and is wheelchair accessible; guided tours are offered for groups of ten or more.

The gable ends carry gargoyles, a detail easy to miss from street level. Weeks designed 21 Carnegie libraries in California, and this one was funded in 1903 and built in 1905. It served as a library until 1955, then became a county historical museum the next year.