It was named for John C. Knox, then President Judge of the judicial district.

The entire township is part of the Allegheny River watershed.

The township contains the unincorporated communities of Knox Dale, Ramsaytown, Barnes, Norman, and Green Valley.

The racial makeup of the township was 99.62% White, 0.09% African American, 0.09% Asian, and 0.19% from two or more races.

22.7% of all households were made up of individuals, and 12.5% had someone living alone who was 65 years of age or older.