Casco is a town in Cumberland County, Maine, United States. The population was 3,469 at the 2000 census. Casco includes the villages of Casco, South Casco and Webb's Mills. The town borders the east shore of Sebago Lake, and is home to part of Sebago Lake State Park.
Casco is part of the Portland–South Portland–Biddeford, Maine metropolitan statistical area.
On January 30, 1767, Raymondtown Plantation was granted by the Massachusetts General Court to Capt. William Raymond of Beverly, Massachusetts and his company of soldiers for their service with Sir William Phipps in the 1690 Battle of Quebec. It replaced a 1735 grant called Beverly-Canada (now Weare, New Hampshire) which was ruled invalid in 1741 because of a prior claim by the heirs of John Mason. In 1803, Raymondtown Plantation was incorporated as Raymond. The town of Naples was created with land taken in 1838, the same year the western half of Raymond petitioned the legislature to be set off as a township because of its geographical separation behind Rattlesnake Mountain. The petition failed, but three years later another was accepted. On March 18, 1841, Casco was incorporated as a town.