Dexter is a village in Jefferson County, New York, United States. The population was 1,120 at the 2000 census. The name is derived from Simon Newton Dexter, one of the village's stockholders.
The Village of Dexter is in the south part of the Town of Brownville and is west of Watertown.
The village was formerly called "Fish Island," and was part of the lands belonging to Jacob and John Brown. The village was renamed "Dexter" after Simon Newton Dexter.