Background: The biopotential of Malaysian green mussels (Perna viridis) has not been fully explored. The aim of the study is to screen the antioxidant capacity of extracts of Malaysian green mussels. Materials and Methods: Mussels were extracted by using solvents such as water, methanol, and ethanol, and methods such as microwave-assisted extraction (MAE) and animal tissue homogenization (ATH) were employed. The percentage yield, total protein content (TPC), total phenolic content, trace element analysis, and biochemical screening of extracts were carried out. The antioxidant capacity of the extracts was assessed by 2,2,-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assay, 2,2'-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid] (ABTS) assay, hydrogen peroxide scavenging assay, and ferric-reducing antioxidant power (FRAP) methods. Results: The yield of extracts prepared by MAE methods was higher than the extracts prepared by ATH methods. The total phenolic contents and TPC were higher in the extracts prepared by ATH method than those prepared by MAE methods. Biochemical screening results revealed the presence of alkaloids, phenolic compounds, and saponins. The percentage radical scavenging and inhibitory concentration50(IC50) values of all extracts were found to be lesser than the standard. Results showed that extracts by ATH methods displayed high antioxidant activity than extracts by MAE methods. The methanolic extracts of P. viridis showed better antioxidant capacity than other extracts in DPPH and ABTS assay methods, whereas the ethanolic extracts displayed high antioxidant activity than other extracts in hydrogen peroxide and FRAP assay methods. The antioxidant activity of the extracts could be attributed to the hydrogen-donating ability of bioactive peptides, phenolic compounds, alkaloids, reducing sugars, and trace elements present in such extracts. Conclusion: The results of the present study lay the platform to isolate newer antioxidants from Malaysian green mussels. It is concluded that extensive mechanistic studies are imminent to ascertain the molecular mechanism involved in the antioxidant activity of such extracts.