The Fifth Maine Regiment Community Center is a historic building at 45 Seashore Avenue on Peaks Island, an island neighborhood of Portland, Maine in Casco Bay. It was built in 1888 by American Civil War veterans "as a memorial to their deceased comrades and as a reunion hall for themselves." It was listed on the National Register of Historic Places in 1978 and designated a Greater Portland Landmark in 1984. Today it is open as a museum.