Grenadier Island Schoolhouse

Grenadier Island Schoolhouse, also known as School No. 16, is a historic one-room school building located on Grenadier Island, Cape Vincent, Jefferson County, New York. It was built about 1879, and is a one-story, two bay by two bay, frame building on a limestone foundation. The building includes a small entrance vestibule and open main classroom space. Also on the property is a contributing original outhouse. It operated until 1942.

It was added to the National Register of Historic Places in 2012.