Lectures on Electromagnetic Theory provides a concise, self-contained introduction to graduate-level electromagnetic theory, organized for a one-semester course. Written in a "theoretical minimum" style, the text emphasizes clear physical insight and mathematical precision. The five chapters cover Maxwell equations and fundamental theorems; wave propagation, plane-wave expansion, and guided waves; electromagnetic radiation and Green functions; analytical scattering theory for canonical targets; and an introduction to relativistic electrodynamics linking classical electrodynamics with special relativity. The book serves both beginning graduate students and researchers seeking a compact reference.