Riverhead (est. 1792) is the County Seat of Suffolk.
The County Center is located in Riverhead, though technically it lies in the Town of Southampton, across the river from downtown Riverhead. Since the post-World War Two population boom in western Suffolk County, many county offices have been moved to or sited in Hauppauge. The Riverhead County Center remains home to the county clerk's office, the office of real property tax services and many divisions of the county health department. The county correctional facility, a medium-security institution, is located adjacent to the county center, along with the Suffolk County Criminal Court.
A branch of the New York State Supreme Court is located on Griffing Avenue in Riverhead, and a branch of Suffolk Family court is located on East Main Street in Riverhead.
This section contains pages that describe government entities and agencies in or affecting the Town of Riverhead, including Riverhead Town government offices, county legislative offices, county departments, as well as state and federal elected officials, including relevant contact information.