The article reviews the recent progress in the synthesis and electrochemical application of transition metal carbides (TMCs) and nitrides (TMNs) for energy storage and conversion. It highlights their electrochemical properties in Li-ion and Na-ion batteries, supercapacitors, and electrocatalytic reactions, such as oxygen evolution and reduction reactions, and hydrogen evolution. The advantages of nanostructuring, particularly 2D MXenes, are emphasized. The article also discusses the crystal structure, morphology, and composition of these materials and their impact on their performance. Finally, it provides an outlook on future research trends in the rational design of high-performance TMCs and TMNs electrodes.The article reviews the recent progress in the synthesis and electrochemical application of transition metal carbides (TMCs) and nitrides (TMNs) for energy storage and conversion. It highlights their electrochemical properties in Li-ion and Na-ion batteries, supercapacitors, and electrocatalytic reactions, such as oxygen evolution and reduction reactions, and hydrogen evolution. The advantages of nanostructuring, particularly 2D MXenes, are emphasized. The article also discusses the crystal structure, morphology, and composition of these materials and their impact on their performance. Finally, it provides an outlook on future research trends in the rational design of high-performance TMCs and TMNs electrodes.