May 21 in the history of the Birmingham District:
- 2011: The 32nd annual Do Dah Day was held.
- 2008: 11th consecutive SEC Baseball Tournament in Hoover began at Regions Park.
- 2006: Walters & Bellows and the Tim Boykin Blues Band performed in the Phelan Park Music Series.
- 2005: Arkansas Twisters 61 - Birmingham Steeldogs 60 at Little Rock, Arkansas.
- 2004: Birmingham Steeldogs 52 - Manchester Wolves 49 at Manchester, New Hampshire.
- 2003: Ruben Studdard was announced as the winner of American Idol.
- 1951: A major fire destroyed a cluster of 20 duplexes in Fairfield while Birmingham Fire Department trucks stood idly by, awaiting Bull Connor's order permitting them to assist.
- 1921: The 1921 National Balloon Race launched from Birmingham, the first event in the city's semicentennial celebrations.
- 1874: Alabama Press Association convention attendees took a train excursion to Blount Springs, with stops at coal mines along the route.