A handkerchief (/ˈhæŋkərtʃɪf/; also called a hankie or, historically, a handkercher or a fogle) is a form of a kerchief or bandanna, typically a hemmed square of thin fabric which can be carried in the pocket or handbag for personal hygiene purposes such as wiping one's hands or face, or blowing one's nose. A handkerchief is also sometimes used as a purely decorative accessory in the breast pocket of a suit; it can then be called a pocket square. A handkerchief is also an important accessory in many folk-dances in many regions like the Balkans and the Middle East; an example of a folk-dance featuring handkerchiefs is the Greek Kalamatianós.

The material of a handkerchief can be symbolic of the socio-economic class of the user, not only because some materials are more expensive, but because some materials are more absorbent and practical for those who use a handkerchief for more than style. Handkerchiefs can be made of cotton, cotton-synthetic blend, synthetic fabric, silk, or linen.

Handkerchiefs are also used as an impromptu way to carry around small items when a bag or basket is unavailable. They could also serve as a substitute for a bandage over a small injury. In the United Kingdom, the habit of wearing a handkerchief with tied corners on one's head at the beach has become a seaside postcard stereotype.

From the late 18th century white handkerchiefs were waved, generally by women (men usually waved their hats), to demonstrate approval at public events such as processions or political rallies.

Using handkerchiefs to accentuate hand movements while dancing is a feature of both West African and African-American traditional dance, in the latter case especially in wedding celebrations. Handkerchiefs are also traditional accoutrements in certain kinds of English folk dance, such as the Morris dance.

Besides their intended use, they could be used for cleaning equipment, polishing shoes, cleaning hands and face, signaling for attention, as a sweat band, neckerchief, as protection from dust inhalation, to repair footwear, cut out pieces to patch clothes, cut up as emergency firearms cleaning patches, Molotov cocktail wick (fire-bomb), hot cooking utensil holder, a makeshift bandage, tourniquet, or arm sling.

In the times of ancient Greece and Rome, handkerchiefs were often used the way they are today.^{[citation needed]}

The word handkerchief derives from the word kerchief which came from a French word: couvre-chef, which means "hat" or "headgear", so a handkerchief is a similar cloth in the hand rather than on the head.