This chapter focuses on MXenes’ applications in water treatment, their potential for purifying water and addressing water pollution challenges. It discusses MXenes’ ability to remove contaminants and enhance water quality, contributing to sustainable development goals related to clean water access. In this chapter, the pollutants are divided into three main categories: heavy metals, organic, and radionuclides pollutants. Various methods for water treatment and pollutants remediations are briefly discussed. Moreover, additional environmental applications, e.g., capacitive deionization, membranes, and antibacterial activity, are explored. The stability of MXenes and MXene-based materials is discussed via studying the regeneration and recycling after adsorption of dyes, heavy metals, and radionuclides. Regarding the future perspectives, there are four main points which are stability, large-scale production, economic feasibility, and application in real wastewater, without a single pollutant. If these issues can be solved, MXenes will be a promising material for water treatment applications.