Progress in research on high‐performance electrochemical energy storage devices depends strongly on the development of new materials. The 0‐dimensional carbon nanomaterials (fullerenes, carbon quantum dots, graphene quantum dots, and “small” carbon nano‐onions) are particularly recognized in this area of research. Their unique properties beneficial for batteries and supercapacitors application are the result of their small and controllable size, ranging from 1 to 10 nm, and their structure. Fullerenes stand out for the particularly precise structure and rich redox properties. Carbon‐based quantum dots and “small” carbon nano‐onions provide a bridge between molecular fullerenes and larger nanostructured carbon systems. For the electrochemical energy storage, 0‐dimensional carbon structures are usually present in nanostructured composites, which ensure high efficiency of devices. In this review, issues related to the contribution of 0‐dimensional carbon materials in improving batteries and supercapacitors. Particular attention has been paid to progress resulting from the use of composites of these carbon nanostructures with other electroactive materials. Much attention has also been devoted to issues related to the synthesis of 0‐dimensional carbon nanostructures enabling the control of their size, chemical composition and surface morphology. Finally, issues requiring additional research are highlighted.