Carbon nanocomposites have gained huge interest in catalysis due to their small size and shape-dependent physicochemical properties. Particularly, metal nanostructures/carbon materials (mainly graphene and carbon nanotubes) based nanocomposites demonstrated extraordinary catalytic activity in organic reactions. The catalytic products prepared by using carbon nanocomposites are found to be highly valuable in various fields including pharmaceutical, biomedical, agricultural, and material sciences. Hence, the demand of carbon nanocomposites has been increasing rapidly, and the development of novel preparation methods also deserve a special concern. In this chapter, we discuss the main advances in the field over the last few years and explore the novel preparation methods of carbon nanocomposites (metal nanostructures/carbon materials) and their applications in various catalytic organic transformations.