The University of San Francisco (USF) is a private Jesuit university in San Francisco, California. The university's main campus is located on a 55-acre (22 ha) setting between the Golden Gate Bridge and Golden Gate Park. The main campus is nicknamed "The Hilltop" and is split into two sections within a block of each other. Part of the main campus is located on Lone Mountain, one of San Francisco's major geographical features. Its close historical ties with the City and County of San Francisco are reflected in the university's traditional motto, Pro Urbe et Universität ('For the City and University').

Founded by the Jesuits in 1855 as St. Ignatius Academy, USF started as a one-room schoolhouse along Market Street in what later became downtown San Francisco. Father Anthony Maraschi, S.J. (1820-1897) was the college's founder and first president, a professor, the college's treasurer, and the first pastor of St. Ignatius Church. Under Maraschi, St. Ignatius Academy received its charter to issue college degrees on April 30, 1859, from the State of California, and signed by governor John B. Weller. In that year, the school changed its name to St. Ignatius College.

The original curriculum included Greek, Spanish, Latin, English, French, Italian, algebra, arithmetic, history, geography, elocution, and bookkeeping.

A new building was constructed in 1862 to replace the first frame building. In June 1863, the university awarded its first Bachelor of Arts degree.

In 1880, the college moved from Market Street to a new site on the corner of Hayes Street and Van Ness Avenue (currently occupied by the Davies Symphony Hall).

The third St. Ignatius College received moderate damage in the 1906 San Francisco earthquake, but was completely destroyed in the ensuing fire. The campus moved west, to the corner of Hayes and Shrader Streets, close to Golden Gate Park. It occupied a hastily constructed structure known as the Shirt Factory (for its resemblance to similar manufacturing buildings of the era) for the next 21 years.

The college moved to its present site on Fulton Street in 1927, on the site of a former Masonic Cemetery.

To celebrate its diamond jubilee in 1930, St. Ignatius College changed its name to the University of San Francisco. The change from college to university was sought by many alumni groups and by long-time San Francisco Mayor James Rolph Jr.

A male-only school for most of its history, USF became fully coeducational in 1964, though women started attending the evening programs in business and law as early as 1927.

In 1969, the high school division, already wholly separate from the university, moved to the western part of San Francisco and became St. Ignatius College Preparatory.

In 1978, the university acquired Lone Mountain College. October 15, 2005, marked the 150th anniversary of the university's founding.