The average auditor salary at Fairfax County was $101,994 , which is 21 percent higher than the average salary for this job in Virginia, and 1 percent higher than the national average for this job . Auditor salaries at Fairfax County typically range from $94,418 to $108,651 (25th to 75th percentile). The highest reported auditor salary was $130,505. There are 16 employees at Fairfax County with the job title auditor.