Physics is the natural science concerned with the study of matter and light and how they interact with each other. That is why physics uses the scientific method to formulate and test hypotheses that are based on observation of nature. The results of these experiments are used to formulate scientific laws expressed in the language of mathematics, which can then be used to predict other phenomena. Physics gives its students depth of thinking, the power of challenge, and the preponderance of logic.

Due to the importance of physics in making a technical leap, King Saud University, represented by the College of Science, sought to open a bachelor's program in physics and astronomy in 1373 AH. Since that time until now, the efforts of the members of the department have been concerted in developing it to achieve the goal of its establishment. Today, the Department of Physics and Astronomy grants a bachelor's degree in physics, a master's degree, and a doctorate.

The Department of Physics and Astronomy at King Saud University is divided into two branches, one of which is for male students and is located at the university headquarters for male students in Diriyah, and the other for female students is located in the University City for female students. Both branches are distinguished by a high-level elite group of academic members and researchers who hold doctoral degrees from international universities. The total number of faculty members is approximately 90 academic and scholarship members, in addition to researchers, technicians and the administrative staff. The Department of Physics is characterized by a study plan for all stages that is comparable to study plans in high-level international universities, and study and research laboratories equipped with the best devices, technologies, and modern programs.

Postgraduate studies include seven different physics tracks based on the research directions of faculty members, which include (theoretical physics - nuclear physics - biomedical physics - environmental physics and renewable energy - laser physics and spectra - materials science - quantum technology - astronomy). All graduate students benefit from working in research laboratories equipped with high-speed lasers, astronomical observatories, nuclear physics laboratories, and more.

The Department of Physics and Astronomy supervises several research chairs, including the Research Chair in Trapology, Genetics, and Surface Sciences, the Early Detection of Cancer Research Chair, and the Renewable Energy Research Chair.