The average cook salary at St. Louis County was $29,718 , which is 26 percent higher than the average salary for this job in Missouri, but 22 percent lower than the national average for this job . Cook salaries at St. Louis County typically range from $19,525 to $39,911 (25th to 75th percentile). The highest reported cook salary was $39,911. There are 2 employees at St. Louis County with the job title cook.