This paper investigates how digital technologies have shaped the concentration of inventive activity in cities across 30 OECD countries. It finds that patenting is highly concentrated: from 2010 to 2014, 10% of cities accounted for 64% of patent applications to the European Patent Office, with the top five (Tokyo, Seoul, San Francisco, Higashiosaka and Paris) representing 21.8% of applications. The share of the top cities in total patenting increased modestly from 1995 to 2014. Digital technology patent applications are more concentrated in top cities than applications in other technology fields. In the United States, which has led digital technology deployment, the concentration of patent applications in top cities increased more than in Japan and Europe over the two decades. Econometric results confirm that digital technology relates positively to patenting activities in cities and that it benefits top cities, in particular, thereby strengthening the concentration of innovation in these cities.