The consumption of foods polluted with different foodborne pathogens such as fungus, viruses, and bacteria is considered a serious cause of foodborne disease in both humans and animals. Multidrug-resistant foodborne pathogens (MRFP) cause morbidity, death, and substantial economic loss, as well as prolonged hospitalization. This study reports on the use of aqueous Rumex leaf extract (ARLE) in the synthesis of silver nanoparticles (ARLE-AgNPs) with versatile biological activities. The synthesized ARLE-AgNPs had spherical shapes with smooth surfaces and an average hydrodynamic size of 27 nm. ARLE-AgNPs inhibited the growth of Escherichia coli ATCC25721, Pseudomonas aeruginosa ATCC27843, Streptococcus gordonii ATCC49716, Enterococcus faecalis ATCC700813, and Staphylococcus aureus ATCC4342. The ARLE-AgNPs were more active against Escherichia coli ATCC25721 than other harmful bacterial strains (26 ± 3 mm). The zone of inhibition for antibacterial activity ranged between 18 ± 3 mm and 26 ± 3 mm in diameter. The nanoparticles’ MIC values varied from 5.19 µg/mL to 61 µg/mL, while their MBC values ranged from 46 µg/mL to 119 µg/mL. The nanoparticles that were created had antioxidant potential. The cytotoxic activity was tested using normal fibroblast cell lines (L-929), and the enhanced IC50 value (764.3 ± 3.9 g/mL) demonstrated good biological compatibility. These nanoparticles could be evolved into new antibacterial compounds for MRFP prevention.