The discovery of two-dimensional (2D) transition metal carbides and nitrides (MXenes) in 2011 has expanded the pool of nanomaterials available for a variety of applications. Characteristic properties of MXenes, such as high conductivity, hydrophilicity and catalytic activity have led to a growing research interest for their use in environmental remediation and water treatment applications. This review summarizes recent advances in the synthesis and applications of MXenes as adsorbents, desalination membranes, electrodes for electrochemical deionization and catalytic or antibacterial agents for water purification and other environmental remediation processes. The overview also features discussions on the computational attempts, biocompatibility and environmental impact in the exploration of MXenes for water applications, highlighting the challenges and opportunities of these advanced 2D materials.