Highest salary at Johnson County in year 2016 was $128,959. Number of employees at Johnson County in year 2016 was 80. Average annual salary was $30,227 and median salary was $24,829. Johnson County average salary is 36 percent lower than USA average and median salary is 43 percent lower than USA median salary. From 2015 to 2016, the average salary of employees at this employer increased 3.4 percent.