William Jefferson Hunsaker (1855–1933) was an American lawyer and politician from San Diego and later Los Angeles, California. Hunsaker was the San Diego County District Attorney from 1882 to 1884, 4th Mayor of San Diego from 1887 to 1888 and president of the California Bar Association from 1913 to 1914.

The mayor of the City of San Diego is the official head and chief executive officer of the U.S. city of San Diego, California. The mayor has the duty to enforce and execute the laws enacted by the San Diego City Council, the legislative branch. The mayor serves a four-year term and is limited to two successive terms.