| Election Name: | 2005 Manihiki by-election |
| Type: | parliamentary |
| Country: | Cook Islands |
| Seats For Election: | Constituency of Manihiki |
| Ongoing: | no |
| Previous Election: | 2004 Cook Islands general election |
| Previous Year: | 2004 |
| Next Election: | 2006 Cook Islands general election |
| Next Year: | 2006 |
| Election Date: | 8 February 2005 |
| Candidate1: | Henry Puna |
| Party1: | Cook Islands Party |
| Popular Vote1: | 120 |
| Percentage1: | 54.55% |
| Candidate2: | Apii Piho |
| Party2: | Democratic Party (Cook Islands) |
| Popular Vote2: | 100 |
| Percentage2: | 45.45% |
| MP | |
| Before Election: | Robert Woonton |
| Before Party: | Democratic Party (Cook Islands) |
| After Election: | Henry Puna |
| After Party: | Cook Islands Party |
The 2005 Manihiki by-election was a by-election in the Cook Islands electorate of Manihiki. It was held on 8 February 2005,[1] shortly after the 2004 general election, and was precipitated by an electoral petition finding the result in the seat to be a dead tie.[2] Both parties to the petition, Prime Minister Robert Woonton and Cook Islands Party leader Henry Puna had agreed that in the event of a draw the question should be decided by the voters, and so Woonton resigned.[2] As a result, Jim Marurai became Prime Minister.[3]
Woonton subsequently decided not to contest the election for personal reasons.[4] The election was won by Henry Puna.[5]