In the current study, selenium nanoparticles (SeNPs) were biosynthesized via extract of baker's yeast (Saccharomyces cerevisiae) for a green, economic, and eco-friendly strategy. The biosynthesized SeNPs were characterized using UV-vis, XRD, FTIR, DLS, and TEM. The particulates showed a spherical morphology with diameters between 4 and 51nm; FTIR studies on NPs show functional groups corresponding to metabolites (proteins), which reduces and stabilizes the nanoparticle. Antimicrobial efficacy of biosynthesized SeNPs against food borne pathogens was assessed. SeNPs showed promising antimicrobial action against food borne pathogens (Escherichia coli, Staphylococcus aureus, Aspergillus fumigatus, and Aspergillus niger) with a minimal inhibitory concentration (MIC) of 62.5, 125, 250, and 500µg/mL against Staphylococcus aureus, Escherichia coli, Aspergillus fumigatus, and Aspergillus niger, respectively. In conclusion, the biosynthesized SeNPs using extract of baker's yeast are promising as a safe antimicrobial agent against food pathogens. Hence, the biosynthesized SeNPs using baker's yeast extract exhibit antimicrobial activities and could be a useful efficacious antimicrobial agent in the preservation of food and medical field.