Suffolk County Historical Society Building

Suffolk County Historical Society Building is a museum and library dedicated to preserving historic artifacts of Suffolk County, New York, as well as other parts of Long Island. It is located at 300 West Main Street as well as Osborn Avenue and Court Street in Riverhead, New York.

Though the museum building itself has only been around since 1930, the Suffolk County Historical Society was established in 1886 by residents of the county who were concerned about preserving its heritage. Riverhead was chosen as the location of the new society because it's the County Seat of Suffolk County, and County Surrogate Judge James H. Tuthill became the first President. The society began collecting items almost immediately, and the first displays were placed in a small glass case in Tuthill’s Riverhead office. Unfortunately, the collection soon outgrew the Judge's office, and in 1893 a small building at the corner of Griffing Avenue and Main Street in Riverhead, which formerly housed the County Clerk's Office, was purchased. Eventually, the growing collection of documents and artifacts outgrew that space too.

The building was designed by August Galow with Colonial Revival styling. It was built on land donated by Alice O. Perkins, the widow of prominent Riverhead resident John Perkins during the 1920s, and was completed in 1930. Extensions were added in 1951 and 1964.

The library boasts more than 20,000 volumes and over 840 cubic feet (24 m³) of manuscripts, including records, ledgers, diaries, maps, atlases, post cards, newspapers, and other paperwork. In 1994, the building was listed on the National Register of Historic Places.