The Act Against Slavery in Upper Canada bans the importation of slaves and will free those who are born into slavery after the passage of the Act at 25 years of age.

The Act Against Slavery was an anti-slavery law passed on July 9, 1793, in the second legislative session of Upper Canada, the colonial division of British North America that would eventually become Ontario. It banned the importation of slaves and mandated that children born henceforth to female slaves would be freed upon reaching the age of 25.