The article is devoted to the analysis of the historical evolution of the treasury system of the Russian Federation and the definition of its role in the modern system of public finance. The study covers the period from Peter the Great's reforms of the 18th century to the digital transformation of the 21st century, revealing the main stages of development, transformation of the structure and expansion of the functional spectrum of the treasury. The paper examines key reforms, including the introduction of the principle of the unity of the treasury, transparency of public finances and the restoration of the treasury system in the post-Soviet period. A comparative analysis of the treasury systems of different countries has been carried out, revealing two main models of organization: the model of administrative directives and the model of agreements. Special attention is paid to the modern digital transformation of the treasury system, including the introduction of cloud technologies, blockchain and big data analytics. The findings of the study highlight the critical role of the Treasury in coordinating inter-budgetary relations, overseeing the targeted use of public funds, and ensuring transparency in the management of public finances.