| Election Name: | 1917 Grey by-election |
| Country: | New Zealand |
| Flag Year: | 2010 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1914 New Zealand general election |
| Previous Year: | 1914 general |
| Next Election: | 1918 Grey by-election |
| Next Year: | 1918 by-election |
| Candidate1: | Paddy Webb |
| Party1: | New Zealand Labour Party |
| Popular Vote1: | elected unopposed |
| Member | |
| After Election: | Paddy Webb |
| Before Election: | Paddy Webb |
| Before Party: | New Zealand Labour Party |
| After Party: | New Zealand Labour Party |
The Grey by-election of 1917 was a by-election held during the 18th New Zealand Parliament.
After the outbreak of World War I, MP Paddy Webb became a leading critic of the Reform government of William Massey's policy of conscription, leading him to be briefly jailed for sedition in April 1917. In October the same year, Webb was called up for the military himself though he refused to co-operate. To back up his decision, he resigned from his seat in Parliament and challenged the government to fight a by-election on the issue in the hopes of gaining a public mandate for his decision.[1] However, Massey's government declined, refusing to make the episode a public one. As a result, Webb was returned to his seat in Parliament unopposed.[2]