The ink secretion of molluscan species was identified as one of the novel sources of bioactive compounds. The present study aims to evaluate the in vitro antioxidant activity of Aplysia depilans ink extract. The antioxidant activity of ink extract were evaluated using 2,2- diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, Hydroxyl radical scavenging activity, Ferric ion reducing power (FRP) and Ferrous ion chelating (FIC) activity. The results from the present work revealed the strongest antioxidant activity of Aplysia depilans ink. The electrophoretic profile showed band with molecular weight of 60 kDa. The highest antioxidant activity in ink extract probably may be due to the presence of this protein with lower moleculair weight.