Newington is a town in Rockingham County, New Hampshire, United States. The population was 811 at the 2020 census. It is bounded to the west by Great Bay, to the northwest by Little Bay and to the northeast by the Piscataqua River. Newington is home to Portsmouth International Airport at Pease and to the New Hampshire Air National Guard. The 110-acre Old Town Center Historic District is listed on the National Register of Historic Places.