In this chapter, the targets and actions for the decarbonization of the Turkish maritime sector and the contribution of the European Commission’s decision titled “Financing Agreement for the Annual Action Plan in favour of Turkey for 2021” to these actions are reviewed. In this context, the research consists of two sections: In the first section, the effects of the acquis communautaire and international agreements on the decarbonization of the Turkish maritime sector are examined. As mentioned in the relevant section, the actions taken for the decarbonization of the Turkish maritime sector are based on the provisions of the United Nations Framework Convention on Climate Change, the Kyoto Protocol, the Paris Agreement, and other international agreements. In addition, the efforts to harmony Turkish law with the regulations on combating climate change of the acquis communautaire of the European Union, which is also a party to the international agreements on climate change, moved Türkiye to the adoption of regulations to reduce greenhouse gas (GHG) emissions including from the maritime sector. In the second section, Türkiye’s strategies for the decarbonization of the maritime sector contained in the Türkiye Green Deal Action Plan, the Twelfth Development Plan and the contribution of the decision of the European Commission titled “Financing Agreement for the Annual Action Plan in favor of Turkey for 2021” to the implementation of these strategies of Türkiye is reviewed. In conclusion, it is found out that the relevant decision of the European Commission will contribute to the fulfilment of the commitments of Türkiye to reduce GHG emissions within the framework of international agreements and to decarbonize the maritime sector, as well as to increase the harmonization of Turkish law with the acquis communautaire.