The intensive utilization of production resources in Kazakhstan’s energy sector and the increase in interdependence between industries make it particularly important to assess the stability and efficiency of the economic system structure. In particular, the coal, petroleum, natural gas and electric power industries constitute the main energy base of the national economy and reflect the interconnection between industries. Therefore, the analysis of intersectoral relationships and structural transformation in the energy sector has become the main direction of modern economic research. In addition, changes in the flow of resources within the energy system directly affect the long-term stability and efficiency of the economy. The purpose of this research is to use a comparative Leontief input-output analysis to examine changes in intersectoral relationships within Kazakhstan’s energy sector and evaluate structural transformations from 2020 to 2024. The methodological basis of this research is a comparative input-output analysis based on the Leontief inter-industry equilibrium framework. This study uses the official statistics of the Republic of Kazakhstan for 2020-2024, including production indicators of the energy sector and intersectoral intermediate consumption data. The analysis is based on a reduced four-sector input-output framework representing the main energy industries of Kazakhstan (coal, oil, natural gas, and electricity), rather than the complete national input-output table. In addition, the intermediate consumption matrix ( Z t ), the technical coefficient matrix ( A t ), the Leontief inverse matrix (( I − A t ) − 1), and backward linkage (BL) and forward linkage (FL) indicators were calculated. The findings reveal that moderate structural adjustments occurred within Kazakhstan’s energy system during 2020-2024. The electricity sector exhibited the highest multiplier effect, confirming its role as the core sector of the system. The obtained results characterize the changing production interdependencies within the energy system, the restructuring of intersectoral linkages, and the systemic evolution of the energy sector.