He was elected to the
Nova Scotia House of Assembly in the
2009 provincial election. He represented the riding of
Colchester-Musquodoboit Valley as a member of the
New Democratic Party until his defeat in the
2013 election. Burrill was the ministerial assistant for the Minister of Community Services (Housing), and chair of the Veteran's Affairs Committee of the Nova Scotia Legislature, in the government of
Darrell Dexter. On June 11, 2015, Burrill announced he was running for the leadership of the Nova Scotia New Democratic Party. On February 27, 2016, Burrill was elected as leader of the party, winning on the second counting of ballots in the
instant-runoff voting system used for this election. In July 2016, Burrill announced that he would seek the NDP nomination in
Halifax Chebucto for the
2017 election. He defeated
Joachim Stroink in the election to return to the legislature. Under Burrill's leadership in the 2017 election, the NDP took seven seats, the same number the party received on election night in 2013 but two more than it held going into the election. In the August 2021 provincial election, Burrill was re-elected, along with five other NDP MLAs, all women. On November 9, 2021, Burrill announced he would step down as party leader, but would remain on until a new leader was chosen at a convention within the year. On May 21, 2022 registration closed for the leadership race, with
Claudia Chender being the sole candidate to replace Burrill. She was confirmed as leader after a general membership vote on June 25, 2022 in Dartmouth and Burrill then formally stepped down as leader. As of September 22, 2024, Burrill serves as the Third Party spokesperson for Seniors and Long-Term Care, Service Nova Scotia and Internal Services, and Fisheries and Aquaculture. He also serves as Caucus Whip for the Third Party. In July 2024, Burrill announced that he would not be seeking reelection in the
next Nova Scotia general election. ==Electoral record==