The Sustainable Development Goals (SDGs) of the United Nations (UN) stand out today as the most needed guiding light in a tormented world facing complex global challenges. These provide an effective roadmap towards a healthier, happier, and progressive society. Microorganisms, being the smallest of living forms, have held the key for ages to a plethora of global game-changing innovations in the quest of sustainable development. In conjunction with nanotechnology, these microbes powerfully open up novel ways to address several UN-SDGs. This chapter sets off a thrilling excursion that reveals the possible contributions of microbial nanotechnology towards humankind via SDG goals. Microbial nanotechnology refers to the process of synthesizing metals, metal oxide, and other relevant nanoparticles using microorganisms, including bacteria, fungi, viruses, and algae. These microbial-assisted nanomaterials have shown incredible success in electronics, catalysis, food sector, health sciences, environment protection, catalysis, and optics. The biosynthesis approach using microorganisms has proved to be eco-friendly, more sustainable, and quicker for producing the desired nanoparticles in contrast to traditional methods, i.e., physical and chemical methods. This chapter furnishes explicit information on how microbes may help in the progress of various SDGs. Also, it covers different strategies involving microbial cells for nanoparticle synthesis, and their applications in healthcare, agriculture, food, energy, and bioremediation. Furthermore, it highlights the importance of conducting ethical research and development to ensure that nanotechnology delivers outcomes that align perfectly with the larger global vision. However, like any other breakthrough, hurdles and barriers in this path would be expected. This chapter openly outlines these challenges which must be taken into consideration to maximize the potential of microbial nanotechnology.