This paper analyzes the potential of solar energy, the existing legal framework, and the state of installed capacities in the Republic of Serbia, in order to determine, through comparison with the European Union (EU) average, the degree of development and to identify opportunities for improving legislation. Solar energy is one of the fastest-growing renewable energy sources (RES) and a key element in achieving the European Union's climate neutrality goals. The study reviews the evolution of EU legislation, from RED I to RED III, together with the REPowerEU plan and the EU Solar Energy Strategy (2022). Serbia's solar potential exceeds the European average by approximately 30%, yet its utilization remains limited. The Law on the Use of Renewable Energy Sources (LURES) has largely transposed the RED II Directive, introducing measures such as the buyer-producer model, guarantees of origin, and market-based incentives. However, delays in adopting by-laws and incomplete harmonization with EU legislation hinder full implementation. The findings support the hypothesis that, despite favorable natural conditions and the existence of a partially harmonized legal framework, the share of solar energy in Serbia's total renewable energy capacity significantly lags behind the EU average, indicating the need for more intensive development of this sector and further alignment with EU legislation.