This study's objective was to evaluate the bioactive compound and antioxidant capacity of Palmaria palmata, Chondrus crispus, and Raphanus sativus leaves extracts. The assay known as 2,2-diphenyl-1-picrylhydrazyl (DPPH) was used to measure antioxidant activity. Methanolic extracts of red algae and radish leaves were examined for their phytochemical and bioactive algal component content as well as their antioxidant capacity. Bioactive substances with a range of characteristics, such as hypocholesterolemic, antibacterial, antiviral, antidiabetic, anticancer, anti-inflammatory, antioxidant, antiobesity, and antimalarial activities, were discovered using gas chromatography-mass spectrometry (GC-MS) investigation. Radish leaf extract had the highest DPPH radical scavenging activity of all the tested samples, with an inhibition rate of roughly 90.67%. According to these findings, the extracts under investigation, particularly those derived from radish leaves and algae, are viable natural sources of bioactive compounds with potential therapeutic uses.