<p>Nano-coating with atomic layer deposition (ALD) has emerged as a pivotal technology for enhancing the performance of a wide range of applications. This review explores recent advancements in ALD nano-coating, with a focus on its high conformality and precision. The review covers key coating techniques and comprehensive methods for analytical coating assessment. The applications discussed include multifunctional coatings, biomedical devices, quantum dot-based technologies, photovoltaic solar cells, energy storage systems, membrane/barrier films, metal–organic frameworks, graphene integration, and sensor technologies. Additionally, the review highlights emerging trends, current applications, and identifies various research gaps, offering insights into potential future directions for ALD nano-coating. The findings underscore ALD’s significant impact in advancing both scientific and industrial applications, while emphasizing the need for continued innovation to address existing challenges.</p>