Black Jack
- County:
- St. Louis County
- County Seat:
- No
- Area (mi²):
- 2.586
- State:
- Missouri
Black Jack is a city located in St. Louis County, Missouri. Black Jack has a 2026 population of 6,575. Black Jack is currently growing at a rate of 0.23% annually but its population has decreased by -1.01% since the most recent census, which recorded a population of 6,642 in 2020.
The median household income in Black Jack is $78,331 with a poverty rate of 5%. The median age in Black Jack is 42.7 years: 42.8 years for males, and 42.5 years for females. For every 100 females there are 85.3 males.