Functionalization of activated carbon as electrode materials for supercapacitor application has attracted much attention nowadays, due to integration of electrostatic and Faradaic reaction mechanism that contributes to high performance supercapacitor system. Thus, this review article aims to provide an up-to-date information on the recent development of nitrogen-functionalized activated carbon and the corresponding techniques (post-modification and in-situ doping) used for the functionalization process. The characteristics of the functionalized activated carbon such as the specific surface area and N-contents, as well as the performance particularly in terms of the gravimetric capacitance has also been discussed. Further, perspective of future work particularly on the nitrogen-functionalized activated carbon has been described at the end of this review paper. Overall, it is hoped that this review paper can enhance the research area on the activated carbon as electrode materials for the supercapacitor applications. © 2020 Elsevier Ltd