Stellar Structure and Evolution, the second volume in the Ohio State Astrophysics Series, takes advantage of our new era of stellar astrophysics, in which modern techniques allow us to map the interiors of stars in unprecedented detail. This textbook for upper-level undergraduate and graduate students aims to develop a broad physical understanding of the fundamental principles that dictate stellar properties. The study of stellar evolution focuses on the 'life cycle' of stars: how they are born, how they live, and how they die. As elements ejected by one generation of stars are incorporated into the next generation, stellar evolution is intertwined with the chemical evolution of our galaxy. Focusing on key physical processes without going into encyclopedic depth, the authors present stellar evolution in a contemporary context, including phenomena such as pulsations, mass loss, binary interactions, and rotation, which contribute to our understanding of stars.