Comprising 440 essays arranged alphabetically in one large volume, this work provides a useful overview of core mathematical background, and applications of nonlinear science to key problems in ecology and biological systems, chemical reaction-diffusion problems, geophysics, economics, electrical and mechanical oscillations in engineering systems, lasers and nonlinear optics, fluid mechanics and turbulence, and condensed matter physics, among others. The Encyclopedia is an essential primary source from which to learn about unfamiliar topics, a useful reference for students and new researchers, and for established nonlinear scientists interested applying methods outside their own specialized areas.