This book is intended as an introductory textbook for graduate students and as a reference book for engineers and scientists working in the field of coastal engineering. As such it gives a description of the theories for wave and nearshore hydrodynamics. It is meant to de-mystify the topics and hence starts at a fairly basic level. It requires knowledge of fluid mechanics equivalent to a first year graduate level. At the end of each topic, an attempt is made to give an overview of the present stage of the scientific development in that area with numerous references for further studies. Contents: **Hydrodynamic Background **Linear Waves **Energy Balance in the Nearshore Region **Properties of Breaking Waves **Wave Models Based on Linear Wave Theory **Nonlinear Waves: Analysis of Parameters **Stokes Wave Theory **Long Wave Theory **Boundary Layers **Nearshore Circulation **Cross-Shore Circulation and Undertow **Quasi-3D Nearshore Circulation Models **Other Nearshore Flow Phenomena