In aged mice, CCN5 overexpression improved skeletal muscle function, reduced myosteatosis (fat mass: p < 0.001; intramyocellular triglyceride: 175.0 ± 11.18 vs. 92.18 ± 10.53 μg/mg tissue, p < 0.001) and restored mitochondrial function.<h4>Conclusions</h4>CCN5 mitigates myosteatosis and counteracts sarcopenia by promoting mitochondrial biogenesis and enhancing LD-Mt interactions through dual pathways, positioning it as a promising therapeutic target for muscle aging and sarcopenia. Here, CCN5 is linked to sarcopenia.