The Saint George Peninsula is situated on the coast south of Thomaston. The area was first explored in 1605. Known as the Lower Plantation of St. Georges, the present towns of St. George and Cushing were incorporated on January 28, 1789 into the Town of Cushing.

Because of the natural boundary the St. George River presented, in April, 1802, a committee recommended the towns be divided. On 7 February 1803, the General Court of Massachusetts passed an act dividing the town of Cushing, and incorporating all that part East of the St. George River into a separate town by the name of St. George (MA Special Laws, 1803, Vol 3, Pg 46). ("Rec of Lower St. George", Aiken)

The first St. George town meeting was held on April 4, 1803. At this meeting the people elected John McKeller, Moderator; John Robinson, Town Clerk; and Joseph Robinson, Hezekiah Prince and John McKeller, Selectmen. ("Hist of St. George", Smalley)

The larger part of the peninsula located at the extreme southern part of Knox County is occupied by the Town of St. George. The town is made up of numerous villages or settlements, namely; Port Clyde, Martinsville, Tenants Harbor, Willardham, Wildcat, Long Cove, St. George (Wiley's Corner), Glenmere, Elmore (Harts Neck), Wallston (Gabbletown), Clark Island, and Spruce Head. The seat of town government is at Tenants Harbor, which is the largest of the villages and, perhaps, the most centrally located. Most people identify the area with a village name rather than the town name of St. George. In addition to the peninsula, a considerable number of islands assist in making up the town's approximate 11,000 acres. The more important of these islands are Whitehead Island, Clark Island, High Island, Northern Island, Southern Island, Mosquito Island, Hupper's Island, Allen Island and Burnt Island. (John Falla)