The 1975 mayoral election was held to select the 37th mayor of San Francisco, and was held in two parts. In the November regular election, then-Speaker of the California State Assembly George Moscone placed first with conservative city supervisor John Barbagelata second and moderate supervisor Dianne Feinstein coming in third. Moscone and Barbagelata thus both advanced to the mandated runoff election in December where Moscone narrowly defeated the conservative supervisor by 4,400 votes, a margin of less than 1%.