This innovative Handbook provides an in-depth exploration of how digital platforms are reshaping cities worldwide. It presents a comprehensive analysis of data-driven urban life, evaluating how platforms including Uber, Airbnb and Google Maps mediate public services, economic activities and social interactions. Leading experts highlight the opportunities and challenges of urban platformisation, examining its economic, political and spatial implications through multidisciplinary insights. Chapters investigate key themes spanning governance, inequality, regulation and digital labour, drawing on a range of global case studies to critically assess how platform urbanism is redefining power structures and access to essential services. The Handbook showcases the influence of digital platforms on cities including Milan, Montréal and São Paulo, focussing on both Big Tech and community-driven alternatives. Ultimately, contributors use diverse methodologies to assess the socio-economic impact of these technologies in cities, analysing the dominance of major platforms alongside local initiatives. The Handbook of Platform Urbanism serves as a crucial reference for scholars and studies of urban studies, political economy, media studies and human and economic geography. Policymakers and practitioners in city governance and urban planning will also benefit from its valuable insights.