Suffolk County is a suburban county located on Long Island, New York, and is the easternmost county in the state. According to the 2010 census, the population was 1,493,350, with a slight decrease to 1,492,953 in 2017. It is the fourth-most populous county in New York. The county seat is Riverhead, although most county offices are located in Hauppauge. The county was named after Suffolk County in England, from which its earliest European settlers originated.
Suffolk County is the largest of Long Island’s four counties and the second-largest of New York State’s 62 counties. It measures 86 miles (138 km) in length and 26 miles (42 km) at its widest point, including water. The county lies within the New York City metropolitan area.
Suffolk is home to several major scientific research facilities, such as Brookhaven National Laboratory in Upton, Cold Spring Harbor Laboratory in Huntington, and the Plum Island Animal Disease Center on Plum Island.
