Incumbent mayor London Breed ran for re-election to a second term in office; she was considered vulnerable, as polls had consistently shown her with low approval ratings.

Breed had also faced criticism for her handling of important issues in the city, including homelessness, crime, and drug addiction.

[3] Polling in June reported that 64% of people did not believe London Breed should be reelected and she had a 66% disapproval rating.

Municipal elections in California are officially non-partisan, though most candidates in San Francisco receive funding and support from various political parties.

The following table shows how votes were counted in a series of rounds of instant runoffs.