Ecological urbanism weds the theory and practice of city design and planning with the insights of ecology and other environmental disciplines.An ecological approach to urban design is not new, but is now critical to the future of the city and its design.Ecological urbanism provides a framework for addressing challenges that threaten humanity, such as global warming, rising sea level, rising energy demands, and environmental justice, while fulfilling human needs for health, safety, and welfare, meaning and delight.This essay describes the roots of ecological urbanism, with an emphasis on the Anglo-American tradition, and identifies fundamental concepts and principles with brief reference to ideas in related fields.This overview provides historical context and a framework to advance the practice of ecological urbanism as a means to achieve cities that are more life-sustaining and more resilient, and less costly to build and maintain.