St. James is a hamlet in Suffolk County, New York, United States. The population was 13,338 at the 2010 census. St. James is part of the Town of Smithtown and is located on the North Shore of Long Island. The ZIP code is 11780.

​The Community Association of Greater Saint James is a way to bring people together who share a passion for making our neighborhood a better place to live. The association will continue efforts to keep our community safe, attractive and a desirable place to live.

The hamlet of St. James in the Town of Smithtown was historically known as Head of the Harbor until 1853. In that year, Episcopalians living in the area organized a parish and incorporated a religious society known as the St. James Church of Smithtown.

In the following year, a church building was constructed on North Country Road and was formally dedicated as the St. James Episcopal Church. The name of St. James seems to have become associated with the community, because soon after this first church was erected, the Federal Government opened its first post office in the area and named the postal district St. James.