Nanotechnology has made serious evolution in several scientific fields. Nanoparticles (NPs) are small-scale compounds having unique characters (at least 100 nm in one dimension). When materials are decreased to the nanoscale, their properties are typically modified, allowing them to act specifically with cell biomolecules. Therapeutic chemicals are loaded into NPs and transported to target cells. Metallic NPs, such as gold, silver, iron, Zn, and metal oxide NPs, have existed serious hurdles in the medical field and their usage in recent years. ZnO nanoparticles (ZnO NPs) have been revealed to show catalytic, electrical, photochemical, anticorrosive, photovoltaic, antifungal, antibacterial, and antiviral characters. ZnO NPs have been utilized in the biomedical field to yield biosensors for many ranges purposes, enhance diagnostics via imaging, regulate medication targeting, and to deliver gene therapy. Multiple studies on the anticancer, antidiabetic, and antibacterial activities of ZnO NPs yield promising scientific data for the treatment of each disease globally. Diabetes mellitus (DM) is a serious health issue that influences people worldwide. The majority of diabetes problems are caused by oxidative stress, which is followed by a decline in cellular zinc levels and zinc-dependent antioxidant enzymes. The pharmacological trials through which ZnO NPs reduce DM and diabetic sequelae are summarized in this review.