Highest salary at Johnson County in year 2021 was $146,073. Number of employees at Johnson County in year 2021 was 259. Average annual salary was $28,896 and median salary was $31,446. Johnson County average salary is 38 percent lower than USA average and median salary is 28 percent lower than USA median salary. From 2020 to 2021, the average salary of employees at this employer increased 10.2 percent, the median salary increased 11.6 percent.