John Dennis McCrate (October 1, 1802 – September 11, 1879) was a United States representative from Maine.
He studied law, was admitted to the bar and practiced in Damariscotta and in Wiscasset.
McCrate was elected a member of the Maine House of Representatives.
He resumed the practice of law in Wiscasset before moving to Boston, Massachusetts, continuing the practice of his profession until 1852 when he moved to Sutton, Massachusetts and engaged in agricultural pursuits.
McCrate died in Sutton, Massachusetts on September 11, 1879, and was interred in Ancient Cemetery in Wiscasset.