Southeast is a town in Putnam County, New York, United States, so named for its location in the southeastern corner of the county. The population was 18,058 at the 2020 census. The town as a whole is informally referred to as Brewster, the town's principal settlement; the latter is also an incorporated village within the town's borders. Interstate 84, Interstate 684, U.S. Route 202, US Route 6, and NY 22 are the primary routes through the town.

Brewster is a village and the principal settlement within the town of Southeast in Putnam County, New York. Brewster’s population was 2,508 at the 2020 census. The village, which is the most densely populated portion of the county, was named for two early farmer landowners, Walter and James Brewster, who donated land for the Brewster railroad station in 1848.