MXenes are two-dimensional (2D) transition metal carbides, nitrides, or carbonitrides that display layered structure, rich surface chemistry, superior hydrophilicity, and intrinsic electronic conductivity. Since the very first report on MXenes (Ti3C2Tx) in 2011, the focus on MXenes has increased exponentially due to their favorable properties for a diverse range of applications including energy storage, thanks to their high conductivity, redox activity, and electrochemically active surface. In this chapter, we have targeted the current advances, achievements, and challenges in MXenes research on supercapacitors in a concise manner. In the beginning, an overview of various synthetic approaches for 2D MXenes are presented, and then, their structural aspects and properties are summarized. Moreover, MXenes and their composites-based supercapacitors are discussed highlighting their potential in such energy storage devices. Finally, few challenges and perspectives are provided to encourage the further improvement of MXenes in supercapacitors.