The knowledge economy is transforming our cities. There has been a paradigm shift, seen in the return of corporate headquarters to urban centers and the proliferation of innovation districts in metropolises round the world. Today, the scientific literature is focused on the metrics of innovation activities from the point of view of human capital and the creative workforce, global economic indicators, companies’ characteristics, scientific production, and how they fit into the urban fabric. However, there is a lack of research that reveals how the knowledge economy has its own urban form, which depends on the characteristics of each place – how innovation activities are more likely to emerge given specific urban conditions. This article aims to situate the emergence of the innovative urban economy in an international context and describe a case study from the metropolitan area of Barcelona, in keeping with the aforementioned hypothesis.