Sag Harbor Municipal Building 55 Main St, Sag Harbor, NY11963 Sag Harbor Village, founded in 1707, staddles the border of Southampton Town and East Hampton Town. The village's…More municipal building includes the clerk's office mayor's office, trustees' office, building department, treasurer, fire marshal and tax assessor. The village board also meets at village hall, on the second floor. The current mayor is Brian Gilbride. Village elections are held the third Thursday in June.