St James is a hamlet and census-designated place in Suffolk County, Long Island, New York. St James is part of the Town of Smithtown and is located on the North Shore of Long Island. The CDP has a total area of 4.5 square miles or 12 km2, no area of water. To the north of the hamlet lies the Village of Head of the Harbor and Stony Brook Harbor. To the east is Centereach, Lake Grove to the southeast, Nenconset to the south, and Village of the Branch to the west.
North Country Road or New York State Route 25A is where the commercial strip is situated and serves as a natural border to the north. Meanwhile, Middle Country Road or New York State Route 25 forms a natural border to the south. Lake Avenue serves as the main thoroughfare traversing north-south, meanwhile, Woodlawn Avenue does west-east. Moriches Road stems from North Country Road to the north and heads southeast passing Mills Pond Road.
The St James General Store, located on Moriches Road, is said to be the oldest continuously operating general store in the United States. Many of these 19th-century structures are located along New York State Route 25A, otherwise known as North Country Road. Among them is Saint James Episcopal Church. In 1873, St James Rail Road Station was established. Although small, the historic station-house is the second-oldest on the Long Island Rail Road. The hamlet is home to Veterans Memorial Park.
Places of education within St James are Saint James Elementary School, Mills Pond Elementary School, Sts. Philip & James School, and Smithtown East High School.
St James Coordinates: 40°52′38″N 73°9′19″W