In the context of global political, economic and social changes, the European Union (EU) represents a unique political and economic association of 27 states, which aims to promote cooperation, peace, stability and prosperity on the European continent. The Republic of Croatia, as a young member of the EU since 2013, actively participates in this dynamic process of integration, striving to achieve common European values and standards. One of the key aspects of Croatia's membership in the EU is access to various funds that the EU provides to support the development of infrastructure, economy, education, environmental protection and other important areas. Through these funds, Croatia has the opportunity to achieve its development goals, improve the quality of life of its citizens and promote sustainable development at the local, regional and national level. In addition, various stakeholders, including regional development coordinators, local development agencies and private consultants, play an important role in the implementation of projects financed from EU funds. Their cooperation and engagement are crucial for the successful implementation of projects and for ensuring transparency, efficiency and compliance with European standards and guidelines. This thesis will investigate the role of the Republic of Croatia as part of the European Union, focusing on the use of EU funds for development support and on key stakeholders in the process of creating and implementing projects in Croatia. It will be analyzed how this cooperation contributes to the progress and improvement of socio-economic conditions in the Republic of Croatia, highlighting the importance of Croatia's integration into the European context and the need for further development and strengthening of cooperation between all relevant actors.