| Election Name: | 1931 Hauraki by-election |
| Country: | New Zealand |
| Flag Year: | 1931 |
| Type: | By-election |
| Ongoing: | no |
| Previous Election: | 1928 New Zealand general election |
| Previous Year: | 1928 general |
| Next Election: | 1931 New Zealand general election |
| Next Year: | 1931 general |
| Turnout: | 8,161 |
| Candidate1: | Walter Massey |
| Party1: | Reform Party (New Zealand) |
| Popular Vote1: | 4,023 |
| Percentage1: | 49.29 |
| Candidate2: | Charles Robert Petrie |
| Party2: | New Zealand Labour Party |
| Popular Vote2: | 2,599 |
| Percentage2: | 31.84 |
| Candidate3: | Ebenezer Allan |
| Party3: | United Party (New Zealand) |
| Popular Vote3: | 997 |
| Percentage3: | 12.21 |
| Member | |
| Before Election: | Arthur Hall |
| After Election: | Walter Massey |
| Before Party: | Reform Party (New Zealand) |
| After Party: | Reform Party (New Zealand) |
| Result: | Reform hold |
The Hauraki by-election of 1931 was a by-election held in the Hauraki electorate during the 23rd New Zealand Parliament, on 27 May 1931. It was caused by the death of incumbent MP Arthur Hall of the Reform Party and was won by Walter Massey.
The following table gives the election results: