The Department of Mathematics is one of the largest Science Departments of Al Kharj College. It was established in 1427 AH (2006). It caters for the education of students of all departments in Al-Kharj colleges, and it teaches more than 30 courses in various disciplines, such as pure mathematics, Applied Mathematics, and Algebra. It is obvious that the graduates of this department have a good opportunity for employment in various places such as the army, Ministry of Education, banks, oil companies, and other place.

Furthermore, the university cares for exceptionally gifted students and offers them scholarships to the developed countries for advanced studies.