Molybdenum sulfide (MoS2)‐based nanocomposites have attracted significant attention for various separation processes due to their ultrathin thickness, high mechanical and chemical strength, and good functionality. Herein, the recent progresses of various fabrication, synthesis, and modification methods for separation membrane‐based on MoS2 nanocomposites are reviewed. Emphasis is given on applications of MoS2‐based membranes in the purification of wastewater, separation of gas mixtures, energy storage separator, and proton‐exchange fuel cells (PEFCs). Advantages and drawbacks of this material for separation applications are discussed. Finally, a future roadmap is suggested for this promising nanomaterial in various separation processes.