| Election Name: | 1904 Pahiatua by-election |
| Country: | New Zealand |
| Flag Year: | 1904 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1902 New Zealand general election |
| Previous Year: | 1902 general |
| Next Election: | 1905 New Zealand general election |
| Next Year: | 1905 general |
| Turnout: | 3,369 |
| Candidate1: | Bill Hawkins |
| Party1: | Independent Liberal |
| Color1: | FFDD00 |
| Popular Vote1: | 1,418 |
| Percentage1: | 42.08 |
| Candidate2: | Lindsay Buick |
| Party2: | New Zealand Liberal Party |
| Popular Vote2: | 1,323 |
| Percentage2: | 39.26 |
| Candidate3: | Samuel Bolton |
| Party3: | Independent politician |
| Popular Vote3: | 476 |
| Percentage3: | 14.12 |
| Member | |
| Before Election: | John O'Meara |
| After Election: | Bill Hawkins |
| Before Party: | New Zealand Liberal Party |
| After Party: | Independent Liberal |
The Pahiatua by-election was a by-election in the New Zealand electorate of Pahiatua, a rural seat at the south-east of the North Island.
The by-election was held on 28 July 1904, and was precipitated by the death of sitting Liberal member of parliament John O'Meara. The election was won by Bill Hawkins who stood as an independent Liberal. Former Wairau MP Lindsay Buick was selected by the government as the official Liberal candidate.
The following table gives the election results: