Dexter is a village located in Jefferson County, New York, within the United States. It sits in the southern part of the town of Brownville, positioned west of Watertown. The community lies adjacent to the Black River, near Black River Bay, which serves as an arm of Lake Ontario. To the south, across the river, the village is bordered by the town of Hounsfield.

The settlement was originally known as Fish Island and was part of the lands belonging to Jacob and John Brown. It was later renamed Dexter after Simon Newton Dexter, one of the village's stockholders. The community became an incorporated village in 1855, at which time it had a population of approximately 528 residents.

The village features the Dexter Universalist Church, which was listed on the National Register of Historic Places in 2003. New York State Route 180 passes through the area, providing north-south connectivity. County Roads 53 and 59 also serve the community, linking it to surrounding regions.

As a small incorporated village, Dexter offers a quiet residential character defined by its historic architecture and riverfront setting. The presence of the historic church provides a cultural landmark for residents and visitors. The community maintains its identity through local governance and historical preservation efforts centered on its founding figures.

According to the 2020 census, Dexter had a population of 1,004. The village is accessible via Routes 180 and 12F, with Watertown located seven miles to the east. Education is provided by the General Brown Central School District. The area experiences four distinct seasons typical of northern New York.