Coasts are often beautiful landscapes with high biodiversity and provide a large and rapidly growing proportion of the world's population with living and working environments, recreation, food, and drinking water. Coasts are also one of the most dynamic natural features on Earth and are under increasing pressure by human activities and climate change. This book compiles the papers that are part of the JMSE Special Issue on Coastal Morphodynamics, launched to compile the current state-of-the-art and future perspectives in the understanding of coastal morphodynamics, the complex and perpetual interaction between waves, tides, currents, sediment, biota, morphology, and humans. A solid understanding of, and skills in, predicting coastal morphodynamics is critical if we wish to manage our coasts in a sustainable manner.