Riyadh International School for Academic Excellence | Mastery. Mastery International School is a leading Riyadh international school committed to delivering high-quality education aligned with global standards. The school emphasizes academic excellence, character building, and critical thinking through a well-designed curriculum. Supported by qualified teachers and modern classrooms, Mastery creates a positive learning environment that encourages student growth, confidence, and long-term success, making it a preferred international school in Riyadh. Website: http://mastery.edu.sa/