The OECD, in co-operation with the EU, has developed a harmonised definition of urban areas that overcomes previous limitations linked to administrative definitions (OECD, 2012). According to this definition, an urban area is a functional economic unit characterised by densely inhabited "city cores" and "commuting zones" whose labour market is highly integrated with the core. The Metropolitan database provides indicators of 649 OECD metropolitan areas identified in 33 OECD countries and the functional urban areas of Colombia. Comparable values of population, GDP, employment, and other indicators are presented.