Built in 1871–72, it is a late work of the noted Portland architect George M. Harding, and one of the city's finest Victorian public buildings.

The Old Saco High School stands on the northwest side of Spring Street, on a parcel that extends between Dyer and Bradley Streets, north of Saco's central business district.

It is a 2-1/2 story brick structure, basically rectangular in shape, with a side-facing slate gabled roof that has brackets and dentil moulding at the eave.

Its main facade, facing Spring Street, is symmetrical, with a central pavilion that rises to a concave mansard roof.

The main entrance is set in the base of this pavilion, in a tall round-arch opening articulated by rustic granite quoining.