Nanotechnology has established various scientific fields, including bio-medical applications, by offering innovative approaches that have greatly improved the diagnosis, therapeutics, and control of diseases such as cancer. Standard practices of traditional therapies for cancer include chemotherapy and radiation. However, these pose a number of problems. These include generalised toxicity, in which normal or healthy cells are destroyed along with the malignant cells; the drug resistance developed by the cancer cells, which gradually makes them less responsive to treatment; and lack of exact localisation, which causes widespread side effects. This implies that there is a continued requirement for more targeted and less harmful drugs for the disease. The emergence of microbial nanomaterials has provided hope for bypassing such restrictions. Unlike the nanomaterials synthesised from chemical sources, microbial nanomaterials come from sources in living microorganisms such as bacteria, fungi, algae, and viruses. These microbes have natural metabolic processes that can produce nanomaterials with discrete physical and chemical characteristics. The “green synthesis”, often known as “biological synthesis of nanoparticles”, has gained popularity as it is an eco-friendly approach that is effortless in making and intrinsically biocompatible. Altered microbial nanomaterials can be utilised to carry therapeutic mediators to selectively target malignant cells, hence adding attractive, lucrative, and supportable management to cancer treatment. This review aims to present a thorough knowledge of the possibilities of microbial nanomaterials in cancer treatment using their production processes, functional characteristics, and therapeutic uses. It investigates possibilities and obstacles for future integration and ways these materials can improve therapy specificity, reduce toxicity, and help eliminate tumours.