
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 2025 population of 6,469. Black Jack is currently declining at a rate of -0.52% annually and its population has decreased by -2.59% since the most recent census, which recorded a population of 6,641 in 2020.
The average household income in Black Jack is $82,156 with a poverty rate of 14.77%. The median age in Black Jack is 30.9 years: 24.3 years for males, and 33.4 years for females.