Nanotechnology has impacted the mechanical engineering field through the integration of new materials and technologies that improve the functionality of mechanical systems. This review focuses on the application of nanotechnology in mechanical engineering taking into consideration major developments, opportunities, limitations, and future direction. Some of these advanced technologies include nanocomposites, nano-coatings, and nanolubricants, which have enhanced the properties and performance of the materials and operations in aerospace, automobiles, and environmental conservation. However, the use of nanotechnology also has its drawbacks, such as manufacturing difficulties, health hazards, and environmental impacts, which require further investigation and legislation. Finally, the paper considers some of the trends in the future that can be associated with smart nanomaterials, nanorobotics, and the use of nano-enhanced renewable energy technologies, which can expand the potential of mechanical engineering. This paper emphasizes the significance of the interprofessional approach and the issues of ethics while the role of nanotechnology in mechanical engineering is growing.