| Type: | presidential |
| Mayor | |
| Before Election: | Angelo Joseph Rossi |
| Before Party: | Republican Party (United States) |
| After Election: | Roger Lapham |
| After Party: | Republican Party (United States) |
| Election Name: | 1943 San Francisco mayoral election |
| Country: | San Francisco |
| Ongoing: | no |
| Previous Election: | 1939 San Francisco mayoral election |
| Previous Year: | 1939 |
| Next Election: | 1947 San Francisco mayoral election |
| Next Year: | 1947 |
| Candidate1: | Roger Lapham |
| Image1: | Roger D. Lapham, 1934.jpg |
| Percentage1: | 41.63% |
| Popular Vote1: | 90,646 |
| Party1: | Republican Party (United States) |
| Candidate2: | George R. Reilly |
| Percentage2: | 26.50% |
| Popular Vote2: | 57,699 |
| Party2: | Democratic Party (United States) |
| Candidate4: | Angelo Joseph Rossi |
| Image4: | Angelo Joseph Rossi 1939.jpg |
| Percentage4: | 21.87% |
| Popular Vote4: | 47,626 |
| Party4: | Republican Party (United States) |
| Candidate5: | Chester MacPhee |
| Image5: | Chester MacPhee.jpg |
| Percentage5: | 9.34% |
| Popular Vote5: | 20,346 |
| Party5: | Nonpartisan candidate |
The 1943 San Francisco mayoral election was held on November 2, 1943. Roger Lapham was elected with 41% of the vote.
| Roger Lapham | 90,646 | 41.63% |
| George R. Reilly | 57,699 | 26.50% |
| Angelo Joseph Rossi | 47,626 | 21.87% |
| Chester MacPhee | 20,346 | 9.34% |