The Maine Celtics, based in Portland, Maine, are a professional NBA G League team that plays home games at the Portland Expo Building and serves as the primary development affiliate of the Boston Celtics. Founded in 2009 as the Maine Red Claws, the team's name was chosen via a fan contest to honor both the region's lobster industry and legendary coach Red Auerbach, and they promptly became a success by selling out a record 48 consecutive home games. The franchise initially shared affiliations with the Charlotte Bobcats and Philadelphia 76ers before becoming solely linked to Boston in 2012, with the Celtics officially purchasing the independently-owned franchise in July 2019. Rebranded as the Maine Celtics in 2021, the team has hit notable milestones, including their first playoff berth in 2013, a franchise-record 11 three-pointers made by Bryce Brown in 2019, and an opt-out of the 2020-21 season due to the pandemic. Recent leadership saw the promotion of Phil Pressey as the 11th head coach in 2025, continuing a long line of coaches that have guided the team through its evolution from an independent D-League team into a fully-owned G League Celtics asset.