General elections were held in the Commonwealth of the Northern Mariana Islands (CNMI) on Saturday, 5 November 2005, electing the Governor and Legislature. There was also a referendum on calling a Constitutional Convention, which was approved by voters. The gubernatorial election was the closest in the commonwealth's history, and resulted in the election of Benigno Fitial, narrowly defeating independent Heinz Hofschneider by 84 votes and incumbent Republican Governor Juan N. Babauta by an additional 98 votes.
The referendum on the Constitutional Convention was called in order to comply with Chapter XVIII, article 2 of the constitution, which required a referendum to be held at least every ten years on convening such a convention. A referendum had been due in 2003 as the last referendum had been in 1993, but the Legislature had failed to organise it.
15,118 people registered with the Election Commission to vote.
Four candidates ran for Governor, each with a running mate: