The transition period from late pregnancy to early lactation in dairy cows involves significant metabolic changes to cope with the challenges related to energy metabolism. Muscle tissue, as the largest energy-metabolizing tissue in dairy cows, plays a crucial role in energy metabolism. Furthermore, circular RNAs (circRNAs) have been shown to play key roles in various biological events. However, the regulatory mechanisms of energy metabolism and muscle cells mediated by circRNAs in the muscle tissue of ketotic dairy cows remain unclear. Here, we identified a total of 5103 circRNAs in the muscle tissue of ketosis-affected cows. Among these, compared to healthy cows, 57 circRNAs were differentially expressed in the muscle tissue of ketosis-affected cows, with 39 upregulated and 18 downregulated. Functional enrichment analysis based on the source genes of circRNAs indicated that circ-30,628 is closely related to carbon metabolism, and circ-CoQ