Urban concentration and economic agglomerationAgglomeration haveUrbanization played an important role in development processes along the last century and were associated with population growthPopulation growth in recent times, suggesting the rising importance of local (non-economic) drivers. The largest metropolitan regionsMetropolitan region, however, seem to deviate from this path and adhere to more individual expansion models. Territorial characteristics may also influence such paths, suggesting how metropolitan growth is broadly heterogeneous and almost unpredictable. Understanding the intimate mechanisms of metropolitan growth means to seriously consider some active constraints to urban expansion such as the available landLand to building, the peculiarity of some local contexts, demographic frictions (e.g. because of aging), and regional planningPlanning. When regions plan to mitigate ecological and socioeconomic risk for resident populationsPopulation, sustainabilitySustainability and resilienceResilience targets should be regarded as intrinsically associated with metropolitan expansion. Based on these premises, the present chapter provides a brief review of theoretical approaches and practical applications alimenting a ‘resilienceResilience debate’ with a specific focus on urban affairs. The ability to adapt to economic/technological change—affecting evolutionary dynamics of regional economies—was intended as a primary key to face with sociopolitical challenges and the demanding request for sustainable developmentSustainable development and environmental quality preservation in metropolitan regionsMetropolitan region.