East Millstone is an unincorporated community and census-designated place (CDP)[7] located in Franklin Township in Somerset County, in the U.S. state of New Jersey.

[11] It is a small rural community that grew and prospered with a small industrial base in the 19th century, centered on the Delaware and Raritan Canal at Amwell Road and the long-abandoned Millstone and New Brunswick Railroad that terminated in East Millstone.

East Millstone maintains its rural character into the 21st century, with a firehouse, a post office and just a handful of local businesses.

The housing stock is also quite old, with no new development in the East Millstone section of Franklin Township in recent years.

It was added to the National Register of Historic Places on March 17, 1983, for its significance in architecture, commerce, industry, and transportation.