The population of Pensacola in 1821 was 695.
Events
- July 17 – U.S. General Andrew Jackson accepts the transfer of Florida from Spain to the United States in Plaza Ferdinand VII and installs a provisional capital in Pensacola
- July 18 – U.S. General Andrew Jackson creates the Pensacola Police Department by appointing a city constable
- December 7 – First Methodist Church is established