The legislators of the European Union (EU) have agreed on the FuelEU Maritime regulation, so far, the worlds most ambitious pathway to maritime decarbonisation. FuelEU Maritime estab-lishes a common EU regulatory framework to stimulate an increased share of renewable and low -carbon fuels in the fuel mix of international maritime transport. This article analyses, through the lens of the Advocacy Coalition Framework, the policy process leading to the political agreement on the FuelEU Maritime regulation. Core beliefs of two different advocacy coalitions including the European Commission, the Council of Ministers, EU Member States, the European Parliament and different IGs are identified like Transport & Environment and the European Community Shipping Association, as are the paths to policy change. The agreement on the FuelEU Maritime regulation follows the Paris Agreement and the following international discussions on how to curb the climate impact from shipping, the presentation of the European Green Deal with a European Climate Law and the presentation of a broad package of EU climate, energy and transport legislation. In addition, it is a result of problem-solving bargaining between the Council of Ministers and the European Parliament.