South Windham is a census-designated place (CDP) in the town of Windham in Cumberland County, Maine, United States. The population of the CDP was 1,374 at the 2010 census.^[2] Prior to 2010, South Windham was part of the Little Falls-South Windham census-designated place.

It is part of the Portland–South Portland–Biddeford, Maine Metropolitan Statistical Area.

South Windham is located at 43°44′10″N 70°25′19″W, along the Presumpscot River. According to the United States Census Bureau, the CDP has a total area of 1.3 square miles (3.3 km²), of which 1.2 square miles (3.1 km²) is land and 0.077 square miles (0.2 km²), or 5.31%, is water.^[3]

The CDP of Little Falls is located directly across the Presumpscot River, in the town of Gorham. U.S. Route 202 and Maine State Route 4 run north-south in a concurrency through both communities.

The Presumpscot River was an early transportation corridor to interior Maine; and provided reliable water power at Little Falls. Major William Knight was operating a sawmill at the falls in 1756. As the local forests were cleared, the sawmill was replaced by William Johnson's grist mill and a wool carding mill operated by Leonard Bacon and Lathrop Crockett. Locks were constructed around the falls to complete the Cumberland and Oxford Canal in 1832.^[5] The canal fell into disuse after the Portland and Ogdensburg Railway was completed through South Windham in 1875.^[6] Maine Central Railroad leased the railway as their Mountain Division in 1888.^[7] Availability of year-round transportation encouraged C.A. Brown and Company to build a large brick wood-paper board factory at South Windham in 1875. Androscoggin Pulp Company purchased the factory, and the industrial village of South Windham developed around the pulp mill.^[8] On April 4, 1919, the legislature passed an act creating the Reformatory for Men at South Windham. It is now the Maine Correctional Center, a minimum to medium security facility for men and women.

• Jeff Donnell, actress (The Iron Maiden, The Amazing Spider-Man, and General Hospital); born in South Windham