James "Sunny Jim" Rolph Jr. was an American politician. A member of the Republican Party, he was elected to a single term as the 27th governor of California from January 6, 1931, until his death on June 2, 1934, at the height of the Great Depression. Previously, Rolph had been the 30th mayor of San Francisco from January 8, 1912, until his resignation to become governor. Rolph remains the longest-serving mayor in San Francisco history.

The mayor of the City and County of San Francisco is the head of the executive branch of the San Francisco city and county government. The officeholder has the duty to enforce city laws, and the power to either approve or veto bills passed by the San Francisco Board of Supervisors, the legislative branch. The mayor serves a four-year term and is limited to two successive terms. Because of San Francisco's status as a consolidated city-county, the mayor also serves as the head of government of the county; both entities have been governed together by a combined set of governing bodies since 1856.