This book describes computational methods used in theoretical physics with emphasis on condensed matter applications. Computational physics involves the use of computer calculations and simulations to solve physical problems. Following an overview of the wide variety of topics and algorithmic approaches studied in this book, the text explores quantum scattering with a spherically symmetric potential as a typical example of a computational physics problem. The next chapters concentrate on electronic structure calculations, presenting the Hartree-Fock and Density Functional formalisms, and band structure methods. Later chapters discuss molecular dynamics simulations and Monte Carlo methods in classical and quantum physics, with applications to condensed matter and particle field theories. Each chapter begins with an exposition of necessary fundamentals, describes the formation of a sample program and ends with problems addressing related analytical and numerical issues. Useful appendices on numerical methods and random number generators are included and the book contains extensive references.