Angus King III, of Portland, announced Tuesday that he is running for governor of Maine in 2026. The son of U.S. Sen. Angus King Jr., King III has experience in business and renewable energy but has never held elected office. Daryn Slover/Portland Press Herald

Angus King III, a businessman, renewable energy entrepreneur and the son of U.S. Sen. Angus King Jr., announced Tuesday that he is running for governor of Maine.

King, a Portland Democrat, joins what is likely to be a crowded field of candidates seeking to replace Democratic Gov. Janet Mills, who will be prevented from running in 2026 because of term limits.

Secretary of State Shenna Bellows, a fellow Democrat, has also announced a campaign for governor, and former Maine Senate President Troy Jackson, also a Democrat, announced in March that he was forming a committee to explore a run .

In all, seven candidates have so far filed campaign finance paperwork with the state for the governor’s race.

“I think people have been struggling in Maine recently,” King said in an interview. “A lot of them are scared and worried and I think we’ve got a pile of challenges ahead of us that are making life really difficult for a lot of Maine people.

“I have spent my career building things that help people and solve problems. … I’m running for governor now to build a better Maine, so that our families can afford to live here and our kids can afford to stay.”

King is the founder and former president of Peaks Renewables, a renewable energy development company that recently spearheaded a project to develop an anaerobic digester to produce natural gas from cow manure in the town of Clinton.

He previously worked at the wind energy company First Wind and as a project developer and partner at the Wishcamper Group, where he was involved in affordable housing development.

“My focus has really been on building things that solve problems and help people, whether it’s affordable housing where we preserve affordability for people and give them a place to live, or a solar and wind company. … It’s always been about building and solving problems,” King said.

King, 54, has not held elected office before but said a perspective from outside state government could be useful in the governor’s office. “I think that’s really what we need to help small businesses and families grow and get ahead,” he said.

If elected, King said his priorities would include lowering the cost of living for working families, solving the housing shortage, and supporting small businesses and helping them grow their work force.

“I’m going to focus on how do we bring costs down, how do we build more housing and how do we build an economy that makes it easier for small businesses to grow and thrive,” he said.

King’s father is an independent who was governor from 1995 to 2003 and who has served as Maine’s junior U.S. senator since 2013.

Sen. Angus King described his son as “hard-working, smart, engaged, and caring” in a written statement.

Angus King III, left, with his stepmother, Mary Herman, center, and his father, Sen. Angus King, right, at the elder King’s campaign headquarters in Portland last fall. Brianna Soukup/Portland Press Herald

“He’s a builder and an optimist who knows Maine and doesn’t quit until the job is done,” Sen. King said. “He’s been building things to take care of people and make the world a better place throughout his life, and I think his combination of smarts, experience, and character will make him an excellent governor of Maine.”

The other candidates who have filed campaign finance paperwork for the race include Bellows and fellow Democrat Kenneth Pinet. The Republicans include Bobby Charles, who served as assistant secretary of state under Colin Powell; Steven Sheppard and Robert Wessels. There is also one unenrolled candidate, Alexander Murchison.

Other Democratic contenders whose names have been floated as potential candidates include U.S. Rep. Jared Golden, D-2nd District, and Hannah Pingree, the director of the Governor’s Office of Policy Innovation and the Future, a former Maine House speaker and the daughter of U.S. Rep. Chellie Pingree.

Speculation about possible Republican candidates has included former U.S. Rep. Bruce Poliquin, Senate Minority Leader Trey Stewart, state Rep. Laurel Libby, and Jonathan Bush, a cousin of George W. Bush who lives in Cape Elizabeth.

State Sen. Rick Bennett and former Senate Majority Leader Garrett Mason, now a lobbyist, have also been mentioned as possible candidates.

Signatures to qualify for the ballot are due to the Maine Department of the Secretary of State by March 16, 2026, and primary elections are scheduled for June 9, 2026.