[2] Black Hawk County is part of the Waterloo – Cedar Falls metropolitan area.

[5] The Cedar River roughly divides the county in half from the northwest to the southeast corner.

73.49% were White, 10.43% were Black, 4.92% were Hispanic, 0.32% were Native American, 2.61% were Asian, 0.65% were Native Hawaiian or Pacific Islander and 7.57% were some other race or more than one race.

There were 51,759 housing units at an average density of 91 per square mile (35/km2).

The racial makeup of the county was 88.42% White, 7.95% Black or African American, 0.18% Native American, 0.98% Asian, 0.04% Pacific Islander, 0.93% from other races, and 1.49% from two or more races.

Black Hawk County is divided into seventeen townships: The population ranking of the following table is based on the 2020 census of Black Hawk County.

As the state swung hard to the right in the 2010s and 2020s, Black Hawk County—as a major population center, in accordance with most other population centers nationwide—has remained staunchly Democratic.