Emancipation Day is celebrated in many former British colonies in the Caribbean and areas of the United States on various dates in observance of the emancipation of slaves of African origin. It is also observed in other areas in regard to the abolition of serfdom or other forms of servitude.

The Slavery Abolition Act 1833 ended slavery in the British Empire on August 1, 1834. Emancipation Day is widely observed in the British West Indies during the first week of August. In many Caribbean countries the Emancipation Day celebration is a part of Carnival, as the Caribbean Carnival takes place at this time (although Carnaval in Trinidad and Tobago takes place in February or March according to Ash Wednesday, not near August).

Some countries observe the holiday as August Monday.

The Slavery Abolition Act 1833 ended slavery in the British Empire on August 1, 1834, and thus also in Canada. However, the first colony in the British Empire to actually abolish slavery was Upper Canada, now Ontario. A British army officer and later the first Lieutenant Governor of Upper Canada (1791–1796), John Graves Simcoe, passed an Act Against Slavery in 1793, which led to the abolition of slavery in Upper Canada by 1810. It was then superseded by the Slavery Abolition Act 1833.