This article provides an in-depth analysis of the theoretical foundations, practical applications, and impact of modern instructional design methodologies on educational effectiveness. In the education system, instructional design serves as a crucial tool for achieving pedagogical goals, enhancing learner comprehension efficiency, and systematically planning the educational process. The research compares major instructional design models including ADDIE, SAM, Design Thinking, and Universal Design for Learning (UDL), examining their advantages and limitations. The article explores theoretical foundations such as cognitive load theory, constructivism, and behaviorist learning theories, demonstrating their application in practical educational projects. The integration of contemporary digital technologies, including adaptive learning systems, gamification, and interactive multimedia tools into instructional design is analyzed. Research findings indicate that purposeful and scientifically grounded instructional design methodologies significantly enhance learner comprehension efficiency, strengthen motivation, and address diverse learning needs.