It is a Queen Anne style building, designed by Jasper D. Sibley and built in 1890.

The Frederick H. Cossitt Library stands in the crossroads village of North Granby, at the southeast corner of East Street (Connecticut Route 539) and North Granby Road (Connecticut Route 189).

It is a two-story wood frame structure, roughly square in plan, with a brick-faced first floor and a clapboarded second level.

The main entrance is on the second level, sheltered by a gabled porch supported by square columns.

Funding for the library was given by Frederick H. Cossitt, a wealthy New York businessman whose family ancestry extends back to Granby in the mid-18th century.