Tom Ashby Keith Buttle The 1957 Auckland City mayoral by-election was held to fill the vacant position of Mayor of Auckland.

The polling was conducted using the standard first-past-the-post electoral method.

The by-election was triggered by the death of sitting Mayor Tom Ashby.

Five candidates put their names forward for the contest, with Deputy-Mayor Keith Buttle elected the new Mayor.

Councillor Dove-Myer Robinson's United Independents (who had backed Ashby a year earlier) ticket chose to neither contest the election nor endorse a candidate.