This paper aims at developing the theoretical framework for linking the CSR of energy utilities with sustainable energy development achievements and at applying this framework in selected countries. The main issues of CSR relevant to the energy sector are discussed, and a comparative analysis of CSR reports of energy utilities and sustainable energy development trends in the Baltic States (Lithuania, Latvia, and Estonia) is performed based on the developed framework. There are three main interlinked sustainable energy development targets: increase in energy efficiency, the use of renewable energy sources, and GHG emission reduction. The significance of CSR in the energy sector is underlined based on the literature review, and the state policies to promote CSR in the energy sector are discussed and critically assessed based on the case studies of three Baltic States. The CSR practices of energy utilities of the Baltic States were assessed and compared with sustainable energy development achievements in these countries, based on the analysis of sustainable energy development trends. Estonia achieved the best results in approaching all sustainable energy development targets and was ranked with the highest scores in CSR ranking among the Baltic States, followed by Lithuania. The results of the case studies demonstrate that the Baltic countries have achieved different results in sustainable energy development progress, and the role of energy utilities and their corporate sustainability practices may have huge impacts on the achievement of sustainable energy development targets.