1820 in Canada

Incumbents

• Monarch: George III, then George IV

Federal government

• Parliament of Lower Canada: 9th then 10th then 11th
• Parliament of Upper Canada: 7th

Governors

• Governor of the Canadas: Robert Milnes
• Governor of New Brunswick: George Stracey Smyth
• Governor of Nova Scotia: John Coape Sherbrooke
• Commodore-Governor of Newfoundland: Richard Goodwin Keats
• Governor of Prince Edward Island: Charles Douglass Smith

Events

• June 18 – The Governor, Earl of Dalhousie, arrives.

Full date unknown

• Creation of the municipality of Prescott and Russell in Upper Canada.
• William Lyon Mackenzie emigrates to Canada.

Births

• January 17 – Hiram Blanchard, Premier of Nova Scotia
• February 17 – Elzéar-Alexandre Taschereau, Archbishop of Quebec
• May 12 – Luc Letellier de St-Just, politician and 3rd Lieutenant Governor of Quebec
• May 19 - Stephen Richards, politician, Ontario MPP for Niagara and Provincial Secretary
• May 30 – Pierre-Joseph-Olivier Chauveau, Premier of Quebec
• July 2 – Oliver Mowat, politician, 3rd Premier of Ontario and 8th Lieutenant Governor of Ontario
• August 2 – John Rose, politician
• August 6 – Donald Alexander Smith, politician
• August 16 – Andrew Rainsford Wetmore, Premier of New Brunswick
• August 27 – Charles-René-Léonidas d'Irumberry de Salaberry, militia officer
• October 13 – John William Dawson, geologist and university administrator
• December 24 – Joseph-Charles Taché, a Canadian noted for his contributions to many aspects of the fabric of Canada

Deaths

• March 12 – Sir Alexander Mackenzie, explorer
• April 8 – Thomas Douglas, 5th Earl of Selkirk, colonizer and author
• July 11 – Frederick Traugott Pursh, botanist