The scope of this chapter is to present an overview of oxidative stress, antioxidants, and the beneficial role of free radicals in the brain. Studies have revealed an alarming increase in oxidative stress due to aging; thus, it initiates damage to cells. A unique defense mechanism known as antioxidants has been developed to counteract the adverse effects of excessive free radical amounts within the body. These naturally occurring substances are readily available within the body or are complementary additions, such as the flavonoids and vitamin E found in food. These substances function to ensure that homeostasis is maintained as well as to protect the body from a range of complications. Cognitive deficiencies, vision loss, responses to stress, immune responses, infertility, and neurological dysfunctions are all complications resulting from the imbalance of free radicals within the body. The brain is deemed at greater risk than other organs, as 20% of the body’s oxygen requirement is allocated to the brain, resulting in an unprecedented amount of free radicals. The brain, as the most metabolically active organ, is adversely affected by an imbalance in free radicals, which are generated due to oxidative stress. Research has revealed the brain’s complex susceptibility to oxidative stress-induced cellular damage that initiates a range of neurological disorders, such as multifactorial aging and neurodegenerative diseases, stroke, migraine headaches, concussions, and neurodevelopmental anomalies. Such cognitive deficiencies are directly linked to the affected brain regions. Consequently, cognitive deficiencies such as memory loss are observed when the neocortex or hippocampus is affected. Antioxidants, derived from food or endogenously present in the body, are necessary for steroidogenesis and neurological pathology. These antioxidants promote cognitive function but could also potentially contribute to treating various neurological disorders and the recovery or aging process.