 The study examined the potential of red algal extract as a source of cobalt oxide nanoparticles, co-304NPs, which can be used for bio-inspired manufacturing and for antioxidant, antibacterial, emolytic potency, and anti-cancer activities. The extracted co-304NPs were characterized by UV vis spectrophotometry, SEM, EDAX, TEM, FDIR, XRD, and TGA. The X-ray diffraction assay revealed that the size of the co-304NPs crystals ranged from 23.2 to 11.8 nanometers. Transmission electron microscopy and scanning electron microscopy images showed that the co-304NPs had a homogenous spherical morphology with an average diameter of 28.8 to 7.6 nanometers. Additionally, the antibacterial activity of co-304NPs was tested using the zone of inhibition, ZOI, method, while its antioxidant capacity was evaluated through the DPPH free radical scavenging assay. This article was authored by Amira K. Hadry, Marzo A. Albalawi, Ifat Al-Sharif, and others.