The "Feynman Lectures on Gravitation" are based on notes prepared during a course on gravitational physics that Richard Feynman taught at Caltech during the 1962-63 academic year. For several years prior to these lectures, Feynman taught about the fundamental problems in gravitational physics, yet he published very little. These lectures represent a record of his viewpoint and some of his insights into gravitation and its application to cosmology, superstars, wormholes, and gravitational waves at that particular time. The lectures also contain a number of digressions and asides on the foundations of physics and other issues.