This chapter examines the European Union’s cohesion policy, aimed primarily at reducing the social and economic differences between EU regions. Academic analysis of cohesion policy has generated insights that have framed wider debates about the nature of the EU as a whole, particularly through the concept of multi-level governance. Moreover, while cohesion policy has taken up a growing share of the EU’s budget, its purpose, effectiveness, and durability have been increasingly challenged. Before analysing these issues, the chapter provides an overview of the emergence of cohesion policy, taking into account the Cohesion Fund and policy reform in the 1990s, 2006, and 2013. It then considers the implementation of cohesion policy and discusses five variants of the modes through which the policy handles day-to-day policy-making: the classical Community method, the regulatory policy mode, the distributional policy mode, policy coordination, and intensive transgovernmentalism.