This book targets practicing structural engineers, graduate students, and graduate university educators with an interest in the seismic response of structures equipped with supplemental damping and seismic isolation systems. The main objective of the book is to familiarize structural engineers with the various innovative systems that have demonstrated considerable potential through analytical studies, experimental testing and actual structural implementation. The discussion focuses on passive energy dissipation systems and seismic isolation systems. Readers of this book should have a strong background on linear and nonlinear dynamic analyses and conventional seismic design to fully appreciate its content. This book can be used as the textbook for the last of a series of graduate courses on the general topic of structural dynamics and earthquake engineering.