Significant regional inequalities of income and wealth exist in every Western European country and in North America, but their extent varies from country to country. In both Europe and the US, it is generally thought that they tended to narrow from the early 1900s until about 1980, since when they have widened. This widening has become associated with the rise of populism, while the Covid-19 crisis has thrown regional disadvantage into sharp relief. This article discusses measurement issues, traces developments over time, and explores the social and economic consequences of regional disparities. It describes the evolution of regional policy, and in particular the move to more localized approaches in Europe, analysing their strengths and weaknesses.