The Doctor of Philosophy (PhD) program in Astronomy and Space Science, launched in the first semester of the 2016 academic year, is the only program in Saudi Arabia that offers a PhD specifically in this field. The program admits applicants who hold a master’s degree with a minimum overall grade of “Very Good” in Astronomy and Space Science, Physics, Mathematics, or Statistics. Building on the department’s long-standing experience in graduate education and research, the program extends the foundations established by the master’s program to a more advanced, specialized, and research-intensive level. The program comprises two specialized tracks: 1. Astrophysics, focusing on the application of physical principles, theoretical models, and astronomical observations to investigate the nature, structure, and evolution of celestial objects and cosmic phenomena. 2. Astrodynamics, emphasizing celestial mechanics, orbital dynamics, and the study of the long-term evolution and stability of dynamical systems in space. Through these tracks, students engage in high-level coursework and original research that deepen their understanding of fundamental physical laws governing cosmic structures and dynamical processes.