This book on Ocean Dynamics, though is a compilation from many sources, it mainly forms part of my personal teaching material at Berhampur University, University of Hyderabad and Arbaminch University. This book will be highly useful for graduate and post graduate students of Oceanography, physical oceanography, meteorology, atmospheric sciences, Aeronautical, Agricultural and space meteorlogy and many other related fields in civil and ocean engineering. Special interest in this book is providing many exercises and their solutions under each chapter for better understanding and applications. This book covers almost all the important topics in physical oceanography like currents with and without friction, upwelling and downwelling, water masses and TS-analysis, waves and tides, Estuaries, internal waves, seiches and storm surges and Rossby and Kelvin waves and related topics. Particular interest and attraction in this book is inclusion of recent developments on North Indian Ocean circulation.