The book "Periodic, Quasi-Periodic and Chaotic Motions in Celestial Mechanics: Theory and Applications" provides a comprehensive overview of the latest developments in celestial mechanics. Written by leading scientists in the field, it addresses both theoretical investigations and practical applications. The outstanding review articles included introduce readers to central topics, including variational approaches for determining periodic orbits, the stability theory of the N-body problem, spin-orbit resonances, and chaotic dynamics. Additionally, the issue of space debris affecting near-Earth space is discussed. This specialized book is aimed at students and professionals interested in the complex motions of celestial bodies.