Littlejohn Island is an island and census-designated place (CDP) in the town of Yarmouth in Cumberland County, Maine, United States.

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

Littlejohn Island is located in Casco Bay at 43°45′41″N 70°7′36″W / 43.76139°N 70.12667°W / 43.76139; -70.12667.

It is connected by a causeway to Cousins Island, which is connected by a bridge to the mainland in Yarmouth.

According to the United States Census Bureau, the Littlejohn Island CDP has a total area of 0.73 square miles (1.9 km2), of which 0.35 square miles (0.9 km2) is the island and 0.39 square miles (1.0 km2), or 53.25%, is in the water surrounding the island.