This textbook provides senior undergraduate and graduate students with an introduction to the basic concepts used the statistical physics of polymers. Methods of Gaussian chain statistics are discussed in detail. Applications to numerous interesting phenomena ranging from the microscopic (chain conformations, biopolymers, etc.) to the macroscopic (phase separations, rheology, etc.) are described. Readers are assumed to have taken elementary courses on statistical physics, quantum physics and mathematical physics, but prior knowledge of polymer science is not required. The book contains many illustrations and diagrams as well as exercises, which will help readers to easily and intuitively understand the concepts described in the text.