The European Atlas of the Seas is a web-based coastal and marine information system, originally aimed at the general public, but capable also of supporting non-specialist professionals in addressing environmental matters, human activities and management policies related to the sea. It is based on a combination of data (and metadata), which present a snapshot of both natural and socio-economic elements of coastal and marine regions in the European Union and its Outermost Regions. The first idea of a European Atlas of the Seas was set forward in 2007 with the launch of the Integrated Maritime Policy for the European Union. Early work on the Atlas was conducted by the Directorate General for Maritime Affairs of the European Commission, while further development of system architecture, data collection, map services and descriptive text was assigned in 2013 to the Joint Research Centre, with the aim to offer new services and features, as well as the interaction with other available information tools. The present European Atlas of the Seas consists of background data layers designed to be displayed as map backdrop, as well as a number of thematic data layers, classified under 8 main categories: geography, nature, tourism, security and safety, people and employment, transport and energy, governance and European policies, fisheries and aquaculture. These can be used to compose customized maps, as user-defined ad hoc indicators, and to probe them with tools such as product-to-product correlations, or time series visualisation. Non-specialist professional users can use such analysis and interpretation capabilities to couple data into ecological and socio-economic indicators for a wide range of applications. The thematic map collection provided a common baseline that can be used by Member States of the European Union in getting started with the Maritime Spatial Planning Directive requirements. As this is seen as a pre-requisite for Blue Growth, the European Atlas of the Seas will help the sustainable use of marine ecosystem services and resources.