Oak Island is located across the Intracoastal waterway from Southport and St. James, about 4 miles southwest of Bald Head Island. Along with Caswell Beach, Oak Island is the longest island in Brunswick County with approximately 18 miles in length. Oak Island was formed when the towns of Long Beach and Yaupon merged. Caswell Beach is where Fort Caswell, a military stronghold that dates back to 1827, is. Today, Fort Caswell is owned by the North Carolina Baptist Assembly.

Oak Island is divided into 3 sections: Oak Island Beach, Oak Island Wooded and Oak Island Mainland. The Beach section is where the great majority of vacation rental homes are located. Most permanent residents live in the wooded or mainland sections. Bordering the wooded section is the Intracoastal waterway thus allowing water access to hundreds of homes with docks. On the mainland, you will find developments such as St. James and South Harbour Village, both of which are Intracoastal Access Marina communities.