Knoxville is a city[3] in Johnson County, Arkansas, United States.

According to the United States Census Bureau, the city has a total area of 2.2 square miles (5.7 km2), all land.

As of the census[6] of 2000, there were 511 people, 194 households, and 138 families residing in the city.

There were 210 housing units at an average density of 94.7 per square mile (36.6/km2).

22.2% of all households were made up of individuals, and 10.3% had someone living alone who was 65 years of age or older.