Wikipedia:Selected anniversaries/September 3
- 1189 - Richard I of England was crowned in Westminster.
- 1783 - Signing of the Treaty of Paris ended the American Revolutionary War.
- 1878 - The passenger steamship Princess Alice sunk in the Thames, over 600 died.
- 1967 - Dagen H in Sweden: traffic changed from driving on the left to driving on the right.
- 1976 - The Viking 2 spacecraft landed on Mars and took the first close-up, color photos of the planet's surface.
Recent days: September 2 – September 1 – August 31