In the past two decades the sports sector has turned its attention to understanding the idea of sustainability, particularly to the practical steps related to this. The purpose of this study is to investigate the nature of CSR (corporate social responsibility) activities carried out by teams playing in the Premier League and the Primera División in the 2018/2019 season, and how these CSR actions serve environmental protection and society, manifesting the concept of sustainable development. We applied comparative analysis based on secondary databases. We examined the available reports regarding all the 40 teams, focusing on information about their CSR aspirations and related academic research results, and we worked out specific criteria to evaluate environmentally and socially related CSR activities. Arsenal and Real Madrid were chosen to show good practices that can serve as examples for the other members of the sports sector. At Premier League clubs, the practical application of the CSR activities has been intensively developed. Clubs share detailed statistical information about their actions, while some of the clubs even publish their future plans. The quantity and detail of the information found with Primera División clubs is rather varied. Some clubs introduce their CSR activities in full detail; however, in the case of most clubs, the accessible information is rather superficial and lacks any exact descriptions. The findings clearly show that the sports world is consciously shifting towards the realization of sustainable development, which requires a comprehensive reconnection of sporting society and an increase in awareness in order to achieve the efficient and successful integration of CSR activities into sport.