| Election Name: | 1990 Auckland City mayoral by-election |
| Country: | New Zealand |
| Flag Image: | Coat of arms of Auckland.svg |
| Type: | Presidential |
| Ongoing: | no |
| Previous Election: | 1989 Auckland City mayoral election |
| Previous Year: | 1989 |
| Next Election: | 1992 Auckland City mayoral election |
| Next Year: | 1992 |
| Election Date: | 8 December 1990 |
| Turnout: | 123,456 (62.42%) |
| Party Name: | no |
| Candidate1: | Les Mills |
| Party1: | Independent |
| Popular Vote1: | 32,839 |
| Percentage1: | 26.59 |
| Candidate2: | Barbara Goodman |
| Party2: | Independent |
| Popular Vote2: | 19,663 |
| Percentage2: | 15.92 |
| Candidate3: | Bruce Hucker |
| Party3: | Community Independent |
| Color3: | B3FFB3 |
| Popular Vote3: | 15,917 |
| Percentage3: | 12.89 |
| Mayor | |
| Before Election: | Catherine Tizard |
| After Election: | Les Mills |
The 1990 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 resignation of sitting Mayor Catherine Tizard after she was appointed to the position of Governor-General. The day of the announcement that Tizard would take up the position, many potential candidates announced their intentions to stand for the mayoralty. Deputy mayor Phil Warren released a press statement form Malaysia, where he was visiting, that he would be a candidate. Tizard's closest rivals in the 1986 and 1989 elections, Marie Quinn and Malcolm Moses, also confirmed they would stand. Councillor Dame Barbara Goodman would not commit, but said she was seriously considering running. Two former borough mayors, Frank Ryan of Mount Albert and David Hay of Mount Roskill, neither ruled out or in a mayoral run. Councillor Grahame Thorne ruled out standing.[1]
Warren led in two opinion polls. The first, in September, had him leading by 15 percentage points over former Mayor of Waitemata Tim Shadbolt who was in second. A second poll a week before voting closed had his lead slip to 8.3% ahead of Goodman who was a close second. Former athlete Les Mills was polling third with Quinn in fourth place and councillor Bruce Hucker fifth.[2]
Twenty candidates came forward for the contest, with businessman and former athlete Les Mills the winner. It was the first Mayoral by-election in Auckland since the death of Thomas Ashby in 1957.
The following table gives the election results:
After Mills won the election it was revealed that he spent $50,000 on his campaign. At the time spending limits were not imposed on local government elections, however unprecedented levels of spending the 1989 and 1990 elections prompted Minister of Local Government Warren Cooper to launch an inquiry on the matter.