Grant Thornton average salary is $70,794, median salary is $65,000 with a salary range from $33,059 to $445,000.Grant Thornton salaries are collected from government agencies and companies. Each salary is associated with a real job position.Grant Thornton salary statistics is not exclusive and is for reference only.rant Thornton average salary is $70,794, median salary is $65,000 with a salary range from $33,059 to $445,000.