| Election Name: | 1987 San Francisco mayoral election |
| Country: | San Francisco |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1983 San Francisco mayoral election |
| Previous Year: | 1983 |
| Next Election: | 1991 San Francisco mayoral election |
| Next Year: | 1991 |
| Election Date: | November 3, 1987 December 8, 1987 |
| Image1: | Agnos (1).jpg |
| Candidate1: | Art Agnos |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 102,898 |
| Percentage1: | 69.92% |
| Candidate2: | John L. Molinari |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 44,275 |
| Percentage2: | 30.08% |
| Mayor | |
| Before Election: | Dianne Feinstein |
| Before Party: | Democratic Party (United States) |
| After Election: | Art Agnos |
| After Party: | Democratic Party (United States) |
An election was held on November 3 and December 8, 1987, to elect the 39th mayor of San Francisco. Dianne Feinstein, then the incumbent, had served as mayor since the 1978 assassination of mayor George Moscone and supervisor Harvey Milk and had been elected to full terms in 1979 and 1983, and was thus term-limited. Then-California State Assembly member Art Agnos came from behind to defeat Supervisor John Molinari, garnering nearly 70 percent of the vote.
| Democratic | Art Agnos | 90,521 | 48.16% | |
| Democratic | John L. Molinari | 46,747 | 24.87% | |
| Nonpartisan | Roger Boas | 40,892 | 21.76% | |
| Nonpartisan | Warren Hinckle | 5,202 | 2.77% | |
| Nonpartisan | Cesar Ascarrunz | 1,483 | 0.79% | |
| Nonpartisan | Will Durst | 1,445 | 0.77% | |
| Nonpartisan | Melissa Ehman | 557 | 0.30% | |
| Nonpartisan | Peter Anestos | 498 | 0.27% | |
| Nonpartisan | Joseph Ryan | 370 | 0.20% | |
| Nonpartisan | Scott D. Redmond | 255 | 0.14% | |
| Total votes: | 193,742 | |||
| Voter turnout: | 51.1% | |||
| Democratic | Art Agnos | 102,898 | 69.92% | |
| Democratic | John L. Molinari | 44,275 | 30.08% | |
| Total Votes: | 153,720 | |||
| Voter Turnout: | 40.3% | |||