The ovaries are defined as the organs that secrete sex hormones and ensure the formation of the ovum in females. The proper functioning of the physiological functions of the ovaries is very important for the health of both the body and the female reproductive system. Reactive oxygen species are produced as byproducts of the normal physiological metabolism of the ovary. Antioxidants are among the factors that work to maintain the balance between the production and excretion of reactive oxygen species. Since the deterioration in the antioxidant system can cause pathological results, antioxidant supplementation is considered a possible strategy for the treatment of reproductive diseases by keeping oxidative stress under control. This chapter provides information about the use of astaxanthin as a natural antioxidant against ovarian damage.