Johnson County Courthouse in Tecumseh, Nebraska; seen from the west. – Ammodramus, Public domain – Wikimedia Commons Johnson County is located in Nebraska. About 5,290 people live here (as of 2020). Between 2010 and 2020, the population grew from 5,217 to 5,290. The area covers about 976.0 square kilometers. The region is divided into 5 Municipalities. The region was founded in 1855. The name originates from Richard Mentor Johnson (vice president of the United States from 1837 to 1841) Johnson County is county in Nebraska, United States. More information at johnsoncounty.ne.gov.