Highest salary at Johnson County in year 2020 was $136,189. Number of employees at Johnson County in year 2020 was 78. Average annual salary was $30,762 and median salary was $30,828. Johnson County average salary is 34 percent lower than USA average and median salary is 29 percent lower than USA median salary. From 2019 to 2020, the average salary of employees at this employer increased 17.1 percent.