This book is devoted to the theory and applications of products of random matrices, which arise naturally in many different fields. It describes analytic and numerical methods for the calculation of the corresponding Lyapunov exponents, which can be used as a tool for the analysis of problems in, for example, statistical mechanics of disordered systems, localization, wave propagation in random media, and chaotic dynamical systems. This book provides an excellent self-contained introduction to the subject for physicists working in condensed-matter and statistical physics.