The town of Riverhead is in Suffolk County, New York, on the north shore of Long Island. The population was 33,506 at the 2010 census. The town is on the mouth of the Peconic River, for which the town is named. Riverhead has been the county seat of Suffolk County since 1727. Riverhead contains the smaller hamlet of Riverhead, which includes the town's principal commercial downtown. Riverhead is located approximately 76 miles(123 km) northeast of New York City and 166 miles (267 km) southwest of Boston via the Orient Point–New London Ferry.