Portland, Maine, held an election for mayor on November 3, 2015. It was the second election since Portland voters approved a citywide referendum changing the city charter to recreate an elected mayor position in 2010.
The new citizen-elected mayor serves full-time in the position for a four-year term, exercises the powers and duties enumerated in Article II Section 5 of the Portland City Charter, be elected using instant-runoff voting, and, like the rest of municipal government in Portland, be officially non-partisan. Ethan Strimling defeated incumbent mayor Michael F. Brennan and fellow challenger Tom MacMillan.
The day after Ethan Strimling announced his candidacy for mayor, a group of city councilors and school board members led by Nicholas Mavodones announced their opposition to the reelection of Mayor Brennan and support of Strimling. Mavodones cited division within the city and city government as well as an atmosphere of frustration under Brennan's leadership. Borth incumbent Brennan and Strimling opposed a $15 minium wage while MacMillan ran on raising the city's minium wage to $15.