<p>The increasing demand for high-performance energy storage devices has spurred extensive research into advanced materials for supercapacitor applications. Among these, MXenes—a family of two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides—have emerged as highly promising electrode materials owing to their outstanding electrical conductivity, hydrophilicity, large interlayer spacing, and tunable surface chemistry. This review comprehensively explores the fundamental electrochemical properties of MXenes, their charge storage mechanisms, and recent progress in the development of MXene-based electrode materials for supercapacitors. Particular emphasis is placed on the multifunctional advantages of MXenes, including their contributions to enhanced energy density, mechanical flexibility, and thermal stability. The review also critically examines key challenges such as structural instability, susceptibility to oxidation, restacking issues, and scalability concerns. To address these limitations, recent strategies involving hybridization with carbon-based materials, metal oxides, and conductive polymers are discussed. Finally, future research directions are proposed to guide the optimization of MXene-based supercapacitors for practical and commercial deployment. Hence, this review provides a comprehensive insight into the pivotal role of MXenes in advancing next-generation supercapacitor technologies.</p>