Encyclopaedia of Statistical Physics is an introduction to physics that has been written primarily for knowledge and self-study. It provides a comprehensive approach to the main ideas of statistical physics at the level of an introductory course. Each chapters of this Encyclopaedia covers the mathematical tools and techniques used by physicists and mathematicians. This Encyclopaedia is intended for graduates and postgraduates science and engineering students of different universities. Since the nature of the subject is abstract, it is introduced through numerical illustration making clear the axioms on which the work is based. The subject matter is presented in a lucid, coherent and logical manner. The text has been written in a simple and lucid form, covering simple and understandable mathematial derivation. This book will be of use to students and professionals in the fields of engineering and physics.