2018 Maine gubernatorial election

The 2018 Maine gubernatorial election took place on November 6, 2018, to elect the governor of Maine. It occurred along with elections for the U.S. Senate, U.S. House, and other state and local elections. Incumbent Republican Governor Paul LePage was term-limited and could not seek a third consecutive term. He later unsuccessfully sought a third term in 2022. This was one of eight Republican-held governorships up for election in a state carried by Hillary Clinton in the 2016 presidential election.

The primaries for this election were the first in Maine to be conducted with ranked choice voting (RCV), as opposed to a simple plurality, after voters passed a citizen referendum approving the change in 2016. An advisory opinion by the Maine Supreme Judicial Court held that RCV would be unconstitutional for general elections for governor and the state legislature. This led state legislators to vote to delay its implementation pending approval of a state constitutional amendment. Backers of a "people's veto" turned in enough signatures to suspend this law until a June referendum vote, which restored RCV for future primary and congressional elections.

Governor Paul LePage threatened not to certify the results of the primary elections, saying he would "leave it up to the courts to decide." He also called the use of ranked-choice voting the "most horrific thing in the world." Secretary of State Matthew Dunlap said the results would be binding regardless of whether LePage certified them.

The Republican nominee was businessman and 2010 independent candidate for governor Shawn Moody. The Democratic candidate was Attorney General Janet Mills. State Treasurer Terry Hayes and businessman Alan Caron had qualified for the ballot as independents, though Caron dropped out on October 29 and endorsed Mills. Former state senator and former mayor of Lewiston and Auburn John Jenkins and perennial candidate Kenneth Capron ran write-in campaigns.

Mills defeated Moody and Hayes with a majority to become the first female governor of Maine. This was the first election since 2006 that Maine elected a Democratic governor. Mills was also the first gubernatorial candidate to win at least 50% of the vote since Angus King in 1998, and the first non-incumbent to do so since Kenneth M. Curtis in 1966. Mills received more votes for governor than any other candidate in Maine history, becoming the first Maine gubernatorial candidate to earn 300,000 votes. This was the first gubernatorial election since 1982 that a Democrat would win a majority of the popular vote.