John McDonell (also spelled Macdonell; November 30, 1768 – April 17, 1850) was a soldier, judge, and political figure in Upper Canada.
By 1778, the family had settled north of the Saint Lawrence River near the current location of Cornwall, Ontario.
Contrary to the usual practice of the time, he had brought his Métis wife, Magdeleine Poitras, back with him from the west.
He opened a general store and also operated a forwarding business for moving goods along the Ottawa River.
In 1816, he became a judge of the Ottawa District court and was elected to the 7th Parliament of Upper Canada representing Prescott.