This book is intended for students interested in the applications of general relativity in astrophysics and cosmology but who would like to avoid mathematical complications. This volume thus combines relativity, astrophysics, and cosmology in a single volume. It provides an introduction to the subject that will enable students to consult more detailed treatises as well as the current literature. For prospective researchers in these fields, the book includes an appendix on differential forms, and an extensive, though not exhaustive list of references. The book is divided into three parts. The section on general relativity gives the case for a curved space-time, presents the mathematical background (tensor calculus, Riemannian geometry), discusses the Einstein equation and its solutions (including black holes, Penrose processes, and similar topics), and considers the energy-momentum tensor for various solutions. The section on relativistic astrophysics discusses stellar contraction and collapse, neutron stars and their equations of state, black holes, and accretion onto collapsed objects. The section on cosmology discusses various cosmological models, observational tests, and scenarios for the early universe.