The Southern Maine Planning and Development Commission is a council of governments serving thirty-nine member municipalities from Kittery, at the southern tip of York County, to Stoneham, at the edge of the White Mountain National Forest.

Founded in 1964 in response to an identified need for a coordinated effort for economic development and resource management, SMPDC has been conducting economic development, housing, and water quality planning and providing technical assistance to the municipalities in the region for over forty-seven years.

The purpose of SMPDC is to strengthen local municipal self-government while combining total resources for meeting regional challenges beyond individual capacities; to serve as a mutual forum to identify, study, and bring into focus regional challenges and opportunities; provide organizational support to enable communication and coordination among governments and agencies concerned with regional issues and opportunities; to act as an advocate where membership directs; and to exercise such powers as the member municipalities may delegate.