Heavy metal pollution has become a serious problem in the environment, especially due to anthropogenic causes. While traditional heavy metal removal methods can be costly and environmentally damaging, phytoremediation is a sustainable and environmentally friendly alternative that removes metals from soil and water using plants' natural capabilities such as bioaccumulation, phytostabilization, and phytodegradation. When heavy metals are taken into plants, they can cause oxidative stress and damage cellular functions. Plants can exert resistance to metal stress by developing defense mechanisms against these toxic effects. Antioxidant systems are one of the most important biochemical mechanisms that protect plants against heavy metal stress. Enzymatic antioxidants and non-enzymatic compounds in plants scavenge free radicals and minimize cellular damage.... In this review, phytoremediation techniques and antioxidant defense mechanisms developed by plants against heavy are discussed. Phytoremediation is a promising, economical, and environmentally friendly method for the removal of heavy metal pollution. However, antioxidant mechanisms that increase the resistance of plants against heavy metal stress play a critical role in the success of phytoremediation. Increasing the antioxidant capacity in plants can improve the efficiency of bioremediation processes and allow for greater metal accumulation. In the future, optimizing antioxidant systems through genetic and biotechnological approaches will allow for more effective and large-scale applications of phytoremediation techniques. Therefore, a better understanding and utilization of antioxidant systems in the fight against heavy metal pollution is of great importance.