The evil eye is a superstitious belief that some people can cause harm to others by looking at them in a certain way. The person who gives someone the evil eye may do so intentionally to cause harm, or unintentionally, as a result of feeling envy toward the person he or she looks at. The victim of evil eye may suffer such effects as general bad luck, disease, or even death.

The most common variant of the evil eye in folklore is that produced by the envious gaze. It is therefore a cautionary tale, against both the sin of envy and that of excessive pride. The curse of the evil eye may be given not only to other people, but also to children, livestock, and inanimate objects that one eyes with envy.

Belief in the evil eye originated in the Middle East, Mediterranean Europe, and South and Central Asia. It features in both Islamic and Jewish lore and has spread to Northern Europe and the Americas. In some areas, blue eyes are thought to be particularly prone to giving the evil eye. This may be because blue-eyed foreigners are likely to be unfamiliar with local customs and taboos regarding looking at others or admiring others' possessions or children.

Folk remedies against the effects of evil eye abound. Kohl, one of the world's oldest cosmetics, has been traditionally applied around the eyes of men, women, and children in the Middle East for centuries as a protection against evil eye. In India, a red pigment called kumkum is applied to the cheeks for the same reason, and in Bangladesh, black dots are painted on children's foreheads to avert evil eye. Many remedies against evil eye involve burning specific substances and/or reciting certain prayers.

Amulets are one of the most common protections against evil eye. In Ancient Rome, various phallic amulets and obscene hand gestures were believed to ward off the curse. Evil eye jewelry is especially common in Turkey, where the blue eye-like design is known as nazar. In the Middle East, an amulet known as the hamsa hand features an eye design and is said to protect the wearer from evil eye. The hamsa hand is religiously significant to both Jews and Muslims.