Butler Point Military Reservation was a coastal defense site located in Marion, Massachusetts as part of the defenses of the Cape Cod Canal.

The Butler Point Military Reservation was built on land purchased in 1942.

Its mission was to protect the southern entrance of the Cape Cod Canal from possible air and naval attack.

It was mirrored at the northern entrance by the Sagamore Hill Military Reservation.

It never fired its guns in anger, but it did play an important part in the defense of the canal.