This paper presents a case study on how Six Sigma methodology can be used to improve student academic performance in three main subjects (Math, Arabic, and English) in a private secondary school located in the Middle East. The Six Sigma methodology of Define, Measure, Analyze, Improve and Control (DMAIC) was used to improve student performance along with several improvement tools such as Fishbone diagram, Pareto charts, and Critical-To-Quality (CTQ) tree. Introducing quality improvement concepts and tools resulted in a series of improvements leading to an increase in student academic achievement quantified by Sigma Quality Level (SQL). The SQL improved in Math from (2.01) to (2.37) and in Arabic from (1.86) to (2.38). On the other hand, English grades did not increase from baseline. The results of this study provide a clear, step-by-step approach to systematically approaching and solving educational problems using the DMAIC model. Practically speaking, the results of this study provides clear evidence that the DMAIC can be used in the educational sector by school administrators and teachers to improve student grades.