Morristown is a town in St. Lawrence County, New York, United States.

The town is named after Gouverneur Morris, a signer of the United States Declaration of Independence and landowner in New York.

The town, part of Macomb's Purchase, was first settled permanently circa 1808 on the site of the present hamlet (and former village) of Morristown.

Due to the lack of waterpower, a windmill was erected in 1828, but stopped working and was abandoned two years later.

The northern town line of Morristown is the international border with Ontario, Canada, defined by the St. Lawrence River.

23.9% of all households were made up of individuals, and 8.8% had someone living alone who was 65 years of age or older.