This book contains a collection of original papers on nonlinear normal modes and localization in dynamical systems from leading experts in the field. The reader will find new analytical and computational techniques for studying normal modes and localization phenomena in nonlinear discrete and continuous oscillators. In addition, examples are provided of applications of these concepts to diverse problems of engineering and applied mathematics, such as nonlinear control of micro-gyroscopes, dynamics of floating offshore platforms, buckling of imperfect continua, order reduction of nonlinear systems, dynamics of nonlinear vibration absorbers, spatial localization and pattern formation in extended systems, singular asymptotics and nonlinear modal interactions and energy pumping in coupled oscillators.