This study attempted to investigate the functionality of Dactylosiphon bullosus, Sporochnus radiciformis, and Zonaria diesingiana extracts among algae as cosmetic ingredients. For this, antioxidant experiments were performed. D. bullosus, S. radiciformis and Z. diesingiana extracts were prepared with a 70% ethanol concentration to measure antioxidant activities. In terms of DPPH radical scavenging activity, Z. diesingiana was the highest with 94.20±0.28%. In ABTS radical scavenging activity, Z. diesingiana was the highest with 96.26±0.98%. In terms of the total phenolic contents and NO radical scavenging activity, Z. diesingiana was the highest with 47.19±2.07 mg gallic acid/g and 92.87±1.79%, respectively. The above results show that Z. diesingiana extract has the greatest antioxidant activity, confirming its potential as a cosmetic ingredient.