Union is a town in Broome County, New York, United States. As of the 2010 census, the town had a total population of 56,346. The name derives from the town having served as a rendezvous for the Sullivan Expedition.
The town is in the south-central part of the county, west of Binghamton. The communities of Union form the western suburbs of Binghamton. Two communities, the villages of Johnson City and Endicott, along with Binghamton, make up the "Triple Cities."