This textbook provides a sound foundation in physical optics by covering key concepts in a rigorous but accessible manner. Propagation of electromagnetic waves is examined from multiple perspectives, with explanation of which viewpoints and methods are best suited to different situations. After an introduction to the theory of electromagnetism, reflection, refraction, and dispersion, topics such as geometrical optics, interference, diffraction, coherence, laser beams, polarization, crystallography, and anisotropy are closely examined.