The EU Regulation on a Single Market for Digital Services (Digital Services Act, the 'DSA') is a comprehensive legal framework to regulate digital services and to tackle illegal activity online across the European Union. The DSA represents one of the main pillars of the EU's reform of the digital single market. It applies horizontally to online intermediaries operating in the EU, including online platforms such as social media, video-sharing platforms, online marketplaces, and search engines. The EU Digital Services Act: A Commentary serves as a reference work on the DSA, written by experts who have been closely involved in all steps of the law-making process, from the preparation of the proposal to the final negotiations, as well as its subsequent elaboration and application. This commentary provides a comprehensive article-by-article analysis that will allow the reader to navigate the provisions of this new, complex legal act. While being novel, the DSA does not enter a completely unchartered territory: numerous provisions draw inspiration from, or are applied together with, the provisions of other Acts and areas of EU law. This Commentary explores the jurisprudential origins of the provisions of the DSA and their articulation with other EU Acts, which will be essential for its interpretation and application. With a foreword by Maciej Szpunar, the First Advocate General at the EU Court of Justice, The EU Digital Services Act: A Commentary strikes a balance between a practical commentary and an academic analysis, and is aimed at legal practitioners, academics, and public authorities.