Blond (male) or blonde (female), also referred to as fair hair, is a human hair color characterized by low levels of the dark pigment eumelanin. The resultant visible hue depends on various factors, but always has some yellowish color. The color can be from the very pale blond (caused by a patchy, scarce distribution of pigment) to reddish "strawberry" blond or golden-brownish ("sandy") blond colors (the latter with more eumelanin). Occasionally, the state of being blond, and specifically the occurrence of blond traits in a predominantly dark or colored population are referred to as blondism.

Because hair color tends to darken with age, natural blond hair is significantly less common in adulthood. Naturally-occurring blond hair is primarily found in people living in or descended from people who lived in the northern half of Europe, and may have evolved alongside the development of light skin that enables more efficient synthesis of vitamin D, due to northern Europe's lower levels of sunlight. Blond hair has also developed in other populations, although it is usually not as common, and can be found among natives of the Solomon Islands, Vanuatu and Fiji, among the Berbers of North Africa, and among some Asians.

In Western culture, blonde hair has long been associated with beauty and vitality. Aphrodite, the Greek goddess of love and beauty, was described as having blonde hair. In ancient Greece and Rome, blonde hair was frequently associated with prostitutes, who dyed their hair using saffron dyes in order to attract customers. The Greeks stereotyped Thracians and slaves as blond and the Romans associated blondness with the Celts and the Germans to the north. In the ancient Greek world, Homer's Iliad presented Achilles as what was then the ideal male warrior: handsome, tall, strong, and blond. In western Europe during the Middle Ages, long, blonde hair was idealized as the paragon of female beauty. The Norse goddess Sif and the medieval heroine Iseult were both significantly portrayed as blonde and, in medieval artwork, Eve, Mary Magdalene, and the Virgin Mary are often shown with blonde hair. In contemporary Western culture, blonde women are often negatively stereotyped as beautiful, but unintelligent.