Knoxville is a town located in the U.S. state of Arkansas. It is within Johnson County. It has a total land area of 2.2 square miles at 35°22′59″N 93°21′57″W. The elevation is 394 feet above sea level. As of the 2010 census data, it had a total population of 731. The population density was 233.65/sq mi. Estimated per capita income in 2015 was $18,718. The average travel time is 26 minutes. It is using Zip code 72845.