This book concentrates on modern topics in statistical physics with an emphasis on strongly-interacting condensed matter systems. The book is self-contained and is suitable for beginning graduate students in physics and materials science or undergraduates who have had an introductory course in statstical mechanics. Phase transitions and critical phenomena are discussed in detail, including mean field and Landau theories and the renormalization group approach. The theories are applied to a number of interesting systems such as magnets, liquids, liquid crystals, polymers, membranes and interacting Bose and Fermi fluids. Disordered systems, percolation and spin of equilibrium concepts are also discussed. Computer simulations of condensed matter systems by Monte Carlo-based and molecular dynamics methods are treated. Each chapter contains a considerable number of exercises. A solution manual is provided.