"Relativistic Astrophysics and Cosmology" offers a succinct and self-contained treatment of general relativity and its application to compact objects, gravitational waves and cosmology. The required mathematical concepts are introduced informally, following geometrical intuition as much as possible. The approach is theoretical, but there is ample discussion of observational aspects and of instrumental issues where appropriate. The book includes such topical issues as the Gravity Probe B mission, interferometer detectors of gravitational waves, and the physics behind the angular power spectrum of the Cosmic Microwave Background (CMB). Written for advanced undergraduates and beginning graduate students in (astro)physics, it is ideally suited for a lecture course and contains 140 exercises with extensive hints. The reader is assumed to be familiar with linear algebra and analysis, ordinary differential equations, special relativity, and basic thermal physics.