Many countries have plans to expand wind energy to meet CO2 emissions targets. Lack of available land area and the need for good and stable wind conditions have stimulated the development of offshore wind turbines, which allows for the development of larger turbines. The offshore environment, however, involves new challenges related to the design, installation, operation and maintenance of the turbines. Based on a graduate-level course taught by the author, this book focuses on the opportunities and challenges related to offshore wind turbines. It introduces the offshore environment, including wind and wave dynamics, before discussing the aerodynamics of wind turbines, hydrodynamic loading, marine operations, and wind farm layout. Featuring examples that demonstrate practical application of the topics covered and exercises to consolidate student understanding, this is an indispensable reference text for advanced students and researchers of environmental science and engineering and for industry professionals working in the wind energy sector.