The Avon by-election was held in 1887 to elect a member for the Avon electorate to the New Zealand House of Representatives, during the 9th session of Parliament. The election was held on 1 June 1887, less than four months before the next general election. Edwin Blake won the election against William Dunlop, with a majority of 3.
| 1887 Avon by-election[1] | ||||||
|---|---|---|---|---|---|---|
| Candidate | Votes | % | ||||
| width=75 | Papanui | width=75 | Riccarton | width=75 | Total | |
| Edwin Blake | 162 | bgcolor=#FFC0CB align=right | 93 | bgcolor=#FFC0CB align=right | 255 | 49.32 |
| William Dunlop | bgcolor=#FFC0CB align=right | 190 | 62 | 252 | 48.74 | |
| Informal votes | align=right colspan=3 | 10 | 1.93 | |||
| Turnout | align=right colspan=3 | 517 | ||||
| Majority for Blake | align=right colspan=3 | 3 | 0.58 | |||
Turnout was particularly low; in the previous election (which Dunlop lost by a greater margin) 731 valid votes (69%) were cast in an electorate of 1,065 voters, while in the following election (held by Blake) 1,428 valid votes (72%) were cast in an electorate of 1,990 voters.