May 21 – Election riots at Montreal. Three supporters of Daniel Tracey of the Parti Patriote are shot dead by government troops. Colonel MacIntosh and Captain Temple are arrested for ordering the shooting. The next day, it is announced that Tracey is elected to the Legislative Assembly for Montreal West.
June – The immigrant ship The Carrick arrives in Quebec filled with Irish immigrants. A few of these immigrants are ill with cholera, which becomes an epidemic in Lower Canada and Upper Canada.
June 20 – Eighty-eight deaths from Asiatic cholera are reported at Montreal.
December – A meeting, at Toronto, proposes annexation of the District of Montreal to Upper Canada.
Full date unknown
7,800 French-Canadians are killed by the cholera epidemic – 3,800 in Quebec and 4,000 in Montreal. Meetings of French Canadians attribute the cholera to British immigrants, 52 000 having arrived in that same year.
The City of Montreal is incorporated. Heretofore an out-port of Quebec, it becomes a port of entry.
William Lyon Mackenzie leaves for England with 25,000 names on the petition advocating more powers for elected representatives, with little result. He is expelled from the Assembly and re-elected while away.