The book "Statistical Physics of Polymers" offers a comprehensive introduction to the statistical mechanics of polymers and complex fluids. It is aimed at students in advanced bachelor's and master's programs, as well as non-specialized researchers who wish to engage in this field. Modern statistical mechanics related to polymers and complex fluids integrates concepts from various disciplines, including chemical physics, statistical mechanics, quantum mechanics, stochastic processes, phase transition theory, hydrodynamics, and rheology. The book conveys fundamental concepts and methods used in current research on the physics of polymers and complex fluids. Through simple yet essential examples, it explains how the physical properties of polymers can be theoretically derived, focusing on the structure and dynamics at mesoscopic levels. These mesoscopic properties are crucial for understanding the physics of polymers and complex fluids, as they reveal universal characteristics that are independent of the microscopic details of the system.