Sun Chlorella is a natural whole food supplement derived from a fresh water single celled green algae called Chlorella pyrenoidosa. The aqueous and organic extracts (hexane and ethyl acetate) obtained from Sun chlorella were screened on reactive oxygen species scavenging capacity, total antioxidant capacity (TAC) and lipid peroxidation inhibition potential. The aqueous extract compared to hexane and ethyl acetate extracts exhibited significant high levels of antioxidant potential, lipid peroxidation inhibition potential along with phenolic and flavonoid contents. In addition, the correlation coefficient between the TAC, phenolic content was found to be significantly positive for the aqueous extract (R2=0.0995) when compared to hexane (R2 =0.016 2), ethyl acetate ( R2 =0.0395 ) extracts. As the aqueous extract of sun chlorella showed significant antioxidant potential by positively modulating the antioxidant activity in vitro ((fish liver homogenate sample) study sample, it is rightly to be considered as a fish feed.