This study explored the potential of cocoa bean husk, a by-product of cocoa processing, as a functional food ingredient. It evaluated how extraction conditions and solvent fractionation affect the content of phenolic compounds and their antidiabetic activity. Cocoa bean husk was extracted using varying concentrations of ethanol (0%, 50%, 70%, and 99%), and the total polyphenol and flavonoid contents were measured alongside the inhibitory activities against α-glucosidase and α-amylase. The extract using 70% ethanol yielded the highest levels of total polyphenols and flavonoids, as well as the strongest inhibitory effects on both enzymes. These findings suggest that aqueous ethanol is more effective than absolute ethanol in extracting bioactive compounds from cocoa bean husk. Following this, the 70% ethanol extract was further fractionated; among the fractions, the ethyl acetate and butanol fractions had the highest total polyphenol and flavonoid contents. Notably, the butanol fraction demonstrated the most significant antidiabetic activity, showing the lowest IC₅₀ values for inhibiting α-glucosidase and α-amylase. This indicates that antidiabetic activity is influenced not only by the total phenolic content but also by the qualitative composition and structural characteristics of the phenolic compounds. Overall, cocoa bean husk shows considerable promise as a value-added functional food ingredient with antidiabetic properties.