| Election Name: | 1900 City of Auckland by-election |
| Country: | New Zealand |
| Flag Year: | 1900 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1899 New Zealand general election |
| Previous Year: | 1899 general |
| Next Election: | 1902 New Zealand general election |
| Next Year: | 1902 general |
| Election Date: | 27 April 1900 |
| Turnout: | 11,000 |
| Candidate1: | Joseph Witheford |
| Party1: | New Zealand Liberal Party |
| Popular Vote1: | 4,927 |
| Percentage1: | 44.79 |
| Candidate2: | Richard Hobbs |
| Party2: | Conservative (New Zealand) |
| Popular Vote2: | 2,823 |
| Percentage2: | 25.66 |
| Candidate3: | James Job Holland |
| Party3: | New Zealand Liberal Party |
| Popular Vote3: | 2,236 |
| Percentage3: | 20.32 |
| Member | |
| Before Election: | William Crowther |
| Before Party: | Independent politician |
| After Election: | Joseph Witheford |
| After Party: | New Zealand Liberal Party |
The City of Auckland by-election was a by-election in the New Zealand electorate of City of Auckland, an urban seat in the Auckland region, in the upper North Island.
The by-election was held on 27 April 1900, and was precipitated by the death of sitting MP William Crowther. The seat was won by Liberal candidate Joseph Witheford who defeated four other candidates including Prime Minister Richard Seddon's personally endorsed candidate, the former Mayor of Auckland James Job Holland.