This paper offers a definition of sustainable development in an ecological economics perspective. For this it begins with a historical analysis of the sustainable development concept from its origins as ecodevelopment to its present formulation as green economy. It follows an assessment of the weak sustainability concept premises which allows for the neoclassical environmental economics not to take into full account the natural reality in its environmental policies proposals. The analysis of the ecological economics theoretical foundations, in turn, has made it possible to conceive a strictly ecological definition of sustainability, a necessary condition for the sustainable development definition proposed. Finally, the paper deals with the problem of slowing down the economy to zero growth without causing a crisis and the problem of changing the consumption expectations in consumption societies. A definition of sustainable development is then proposed.