| Election Name: | 1915 Taumarunui by-election |
| Country: | New Zealand |
| Flag Year: | 1915 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1914 New Zealand general election |
| Previous Year: | 1914 general |
| Next Election: | 1919 New Zealand general election |
| Next Year: | 1919 general |
| Turnout: | 4,551 |
| Candidate1: | William Jennings |
| Party1: | New Zealand Liberal Party |
| Popular Vote1: | 2,853 |
| Percentage1: | 50.95% |
| Candidate2: | Charles Wilson |
| Party2: | Reform Party (New Zealand) |
| Popular Vote2: | 2,643 |
| Percentage2: | 47.20% |
| Member | |
| Before Election: | William Jennings |
| After Election: | William Jennings |
| Before Party: | New Zealand Liberal Party |
| After Party: | New Zealand Liberal Party |
The Taumarunui by-election of 1915 was a by-election during the 18th New Zealand Parliament in the electorate. It was held on the 15 June 1915. The seat had become vacant in May 1915 when incumbent Taumarunui MP's William Jennings' election the previous year was declared void. Jennings stood again and successfully retained his seat.
The following table gives the election results: