The synthesis of carbon nanospheres (CNS) has developed rapidly in recent years, and they are widely used owing to the tunability of their porous structures and surface properties and the unique hydrodynamic advantages conferred by their spherical structures. This review summarizes the methods used to synthesize CNS and their applications in various fields. The review first describes the four main methods of CNS synthesis, i.e. the template, spray-drying, hydrothermal carbonization, Stöber and chemical vapor deposition method. Next, applications in the fields of energy storage, adsorption, biological medicine, and catalysis are expounded. Finally, some insights on the development and design of CNS are presented.