In the dynamic realm of chemistry, the quest for environmentally friendly and energy-efficient alternatives in organic synthesis remains paramount. Photocatalysis emerges as a promising solution to these challenges, as evidenced by recent scientific achievements in this area. A large extends of homogeneous and heterogeneous photocatalysts have been expanded and utilized for visible-light-induced organic reactions. Each photocatalyst possesses unique advantages and disadvantages. Semiconductor nanostructured materials, owing to their appealing attributes such as efficiency, affordability, safety, tunability in band gaps, capacity to generate charge carriers under visible light, exposed active sites, high photon absorption capability, ease of preparation, and large surface area, have emerged as particularly promising candidates for photo-driven organic reactions. In this chapter, we offer an extensive summary of nano-photocatalysis in organic transformations, focusing on various nano-semiconductor photocatalysts including CdS, Cu: ZnS, InP/ZnS QD, CdSe, ZnSe/CdS, carbon quantum dots, perovskites, carbon nano-onions, and g-C3N4, among others. Additionally, we highlight several strategies such as morphology control, bandgap engineering, crystal facets, functional groups, surface vacancies, and the loading of metal/non-metal nanoparticles as co-catalysts, aimed at enhancing the photocatalytic activity of nano photocatalysts. It is our hope that this chapter will provide valuable insights for the development of novel photocatalysts for visible-light-driven organic synthesis.