The article examines the legal regulation of the financial and budgetary sphere, which is ensured by a multi-level hierarchical system of normative acts — from constitutional norms to sub-legislative acts of executive authorities. The doctrinal approaches of Russian scholars (E.Yu. Gracheva, E.D. Sokolova, N.I. Khimicheva, E.V. Pokachalova, S.V. Zapolsky, Yu.A. Krokhina, N.D. Eriashvili) to the concept of finance and the financial system of the state are analyzed. A distinction is made between the categories “financial sphere” and “financial-budgetary sphere”; the author's definition of the financial-budgetary sphere is proposed as a set of public relations, regulated by the norms of financial, budgetary and tax law, arising in the process of formation, distribution and use of state and municipal monetary funds. The subject, object composition and legal basis of the financial-budgetary sphere are characterized, as well as its structural elements — the budget system, state extra-budgetary funds, revenue and expenditure blocks, state financial control, the institute of state and municipal debt. The protective function of the principles of the budget system is substantiated: violation of the principles of targeting, purposefulness and efficiency of using budget funds forms the content of most financial-budgetary offenses and crimes, including those provided for in Articles 285.1 and 285.2 of the Criminal Code of the Russian Federation. The role of state financial control as a structural element of the system of protection of the financial-budgetary sphere and the most important source of criminalistically significant information in the detection and investigation of crimes in this area, including in the context of rapidly developing digitalization of control activities, is separately substantiated. Theoretical and applied conclusions are formulated, creating the basis for subsequent criminalistic analysis of crimes in the financial-budgetary sphere.