Nanotechnology has the ability to manipulate matter at the nanoscale and can revolutionize various fields such as medicine, energy, electronics, and materials science by enabling the development of new novel materials, devices, and technologies with unique properties and functionalities. This research paper describes an eco-friendly method of synthesizing silver-copper oxide bimetallic nanoparticles using domestic/industrial waste of orange (Citrus sinensis (L.) Osbeck) peels extract that act as the reducing and stabilising agents. The nanoparticles were successfully synthesized and characterized using various techniques such as UV–Vis spectroscopy, Fourier transformation infrared spectroscopy—FTIR, energy dispersive X-ray spectroscopy—EDX, X-ray diffraction—XRD, and field emission scanning electron microscopy—FESEM. Further synthesised bimetallic nanoparticles were used to evaluate the antibacterial, antioxidant and catalytic activity. Results exhibited enhanced antioxidant activity, dye degradation of methyl red, phenol red, and eosin yellow, and antibacterial activity against Staphylococcus aureus, Bacillus subtilis, and Klebsiella pneumonia. Ag–CuO bimetallic nanoparticles displayed a higher scavenging activity of 63.87% at 500 µg/ml. Maximum amount of degradation was obtained in case of phenol red dye i.e., 88.4% and in 30 min. Bacillus subtilis showed the highest zone of inhibition (18 mm) at 200 µl/ml of nanoparticles concertation. Therefore, Ag–CuO bimetallic nanoparticles synthesised from the orange peels might serve as a novel antioxidant, antibacterial and catalytic agent in the treatment of wastewater contaminated with dyes.