The Whitlocks Mill Light is a lighthouse on the south bank of the St. Croix River in Calais, Maine.

The keeper's house, now privately owned, is an L-shaped two-story gambrel roof oriented to face the river.

The tower is a circular brick structure, topped by a lantern house surrounded by an iron railing.

[7] In 1969 the light was automated, and the Fresnel lens was replaced with a standard 9.8 inches (250 mm) optic.

[6] In 1970, the station was leased to the Washington County Vocational Technical Institute;[2] eventually the keeper's house and grounds passed into private hands, but the Coast Guard retained ownership of the light tower itself.