Marine microorganisms are gradually recognized as a prolific source of bioactive compounds with promising applications in therapeutic research. In this study, a marine bacteria Bacillus subtilis was isolated and identified using 16S rRNA sequencing for the production of bioactive compound Coumarin derivative. The compound Coumarin derivative (2H-1-Benzopyran-2-one, 3-amino-4-hydroxy), was extracted using solvent extraction, column purification method and identified through UV Spectrometry, FTIR and GCMS analysis, the Spectrometric characterization confirmed the presence of amino and hydroxyl substitutions on the Coumarin core, enhancing the compound’s biological profile. It exhibited significant antimicrobial action against test microorganisms and cytotoxic activity against (MDA-MB-231) human breast cancer cell line. These findings highlight the potential of marine Bacillus subtilis derived Coumarin as lead molecules for developing dual-purpose antimicrobial and anticancer therapeutics.