Captain John McDonell of Aberchalder (also spelled MacDonell; c. 1758-21 November 1809) was a soldier, judge, and political figure in Upper Canada following the American Revolution.
When the Treaty of Paris ended the American Revolution in 1783, McDonell settled with other Highlander Loyalists along the St. Lawrence River in Upper Canada.
He played an important role in the local militia, commanding the Upper Canada Battalion of the Royal Canadian Volunteer Regiment.
In 1792, McDonell and his brother Sir Hugh MacDonell of Aberchalder were elected to the Legislative Assembly representing Glengarry.
John McDonell of Aberchalder died of what was described as a "severe cold" at Quebec City in 1809.