Circular RNA (circRNA) has a significant impact on the maturation of skeletal muscle, although their precise functions within this framework remain largely uncharted. This study presents an investigation of the regulatory effect of circAGGF1 on myogenesis in myoblasts, including the potential molecular mechanisms involved. It is revealed that circAGGF1 facilitates the differentiation of myoblasts into other states while simultaneously enhancing the manifestation of type I muscle fibers. In vivo investigations with mice revealed the promotion of skeletal muscle expansion and maturation by circAGGF1, bolstering its regenerative capacity. Mechanistically, circAGGF1 interacts with miR-199a-3p by acting as a sponge, promoting the subsequent expression of Fgf7. Furthermore, rescue experiments indicated a counteraction of the myogenesis induced by circAGGF1 overexpression by miR-199a-3p. To summarize, this research highlights the role played by circAGGF1 in the development of skeletal muscle, providing a valuable resource for enhancing our understanding of skeletal muscle biology.