Barley sprouts, rich in bioactive compounds, have gained attention as functional food ingredients because of their antioxidant potential. This study evaluated their bioactive composition and antioxidant capacity, focusing on the saponarin, chlorophyll, policosanol, total polyphenol (TP), and total flavonoid (TF) contents. The antioxidant capacity was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric-reducing antioxidant power (FRAP) assays. The results showed that barley sprouts contained 8.14 ± 0.02 mg/g of saponarin, 15.36 ± 0.18 mg/g of total chlorophyll, 396.99 mg/100 g of policosanols, 12.64 ± 0.04 mg of gallic acid equivalent (GAE)/g, and 5.99 ± 0.09 mg of rutin equivalent (RE)/g. The half-maximal inhibitory concentration (IC50) values exhibited the trend FRAP > DPPH > ABTS. Significant correlations (R > 0.891, p < 0.05) were observed between the antioxidant assays and TP and TF contents, indicating their substantial role in the antioxidant properties of barley sprout extracts. These findings suggest that barley sprouts are a valuable natural source of antioxidants for functional food applications. Nevertheless, additional in vivo and clinical research is necessary to improve their bioavailability and expand their potential use in food formulations.