Brian Hubbell represented Bar Harbor in the state legislature for four terms, serving on the Appropriations Committee and the Education Committee. 

As a legislator, he co-chaired the legislature's 2014 commission on school funding and represented the legislature on the Maine Economic Growth Council, the Scientific and Technical subcommittee of the Maine Climate Council, and the Governor's 2020 Economic Recovery Committee. 

In 2004, he was part of the working group that developed Maine's first climate action plan.

In the 131st Legislature, he was the Speaker's budget policy advisor.