Cornrows (also called canerows) are a style of three-strand braids in which the hair is braided very close to the scalp, using an underhand, upward motion to make a continuous, raised row. Cornrows are often done in simple, straight lines, as the term implies, but they can also be styled in elaborate geometric or curvilinear designs. They are considered a traditional hairstyle of African braiding practice in many African cultures, as well as in the African diaspora. They are distinct from, but may resemble, box braids, Dutch braids, melon coiffures, and other forms of plaited hair, and are typically tighter than braids used in other cultures.

The name cornrows refers to the layout of crops in corn and sugar cane fields in the Americas and Caribbean, where enslaved Africans were displaced during the Atlantic slave trade. According to Black folklore, cornrows were often used to communicate on the Underground Railroad and by Benkos Biohó during his time as a slave in Colombia. They often serve as a form of Black self-expression, especially among African Americans, but have been stigmatized in some cultures. Cornrows are traditionally called "kolese" or "irun didi" in Yoruba, and are often nicknamed "didi braids" in the Nigerian diaspora.

Cornrows are worn by both sexes, and are sometimes adorned with beads, shells, or hair cuffs. The duration of braiding cornrows may take up to five hours, depending on the quantity and width. Often favored for their easy maintenance, cornrows can be left in for weeks at a time if maintained through careful washing of the hair and natural oiling of the scalp. Braids are considered a protective styling on African curly hair as they allow for easy and restorative growth; braids pulled too tightly or worn for longer lengths of time and on different hair types can cause a type of hair loss known as traction alopecia.

Cornrows originated in Africa, where they likely developed in response to the unique textures of African hair, and have held significance for different cultures throughout recorded history. Early depictions of women with what appear to be cornrows have been found in Stone Age paintings in the Tassili Plateau of the Sahara, and have been dated as far back as 3000 B.C. A similar style is also seen in depictions of the ancient Cushitic people of the Horn of Africa, who appear to be wearing this style of braids as far back as 2000 B.C. In Nubia, the remains of a young girl wearing cornrows has been dated to 550–750 A.D. Cornrows have also been documented in the ancient Nok civilization in Nigeria, in the Mende culture of Sierra Leone, and the Dan culture of the Côte d'Ivoire.

Women in West Africa have been attested wearing complex hairstyles of threaded or wrapped braids since at least the 18th century. These practices likely influenced the use of cornrows and headwraps (such as durags) among enslaved Africans taken to the Americas. In Ethiopia and Eritrea, there are many braided hairstyles which may include cornrows or "shuruba", such as Habesha or Albaso braids, and Tigray shuriba. Though such hairstyles have always been popular with women, Ethiopian men have also worn such hairstyles. In 19th century Ethiopia, male warriors and kings such as Tewodros II and Yohannes IV were depicted wearing braided hairstyles, including the shuruba.

Cornrow hairstyles in Africa also cover a wide social terrain: religion, kinship, status, age, racial diversity, and other attributes of identity can all be expressed in hairstyle. Just as important is the act of braiding, which passes on cultural values between generations, expresses bonds between friends, and establishes the role of professional practitioner. Braiding is traditionally a social ritual in many African cultures—as is hairstyling in general—and is often performed communally, as White and White explain:

In African cultures, the grooming and styling of hair have long been important social rituals. Elaborate hair designs, reflecting tribal affiliation, status, sex, age, occupation, and the like, were common, and the cutting, shaving, wrapping, and braiding of hair were centuries-old arts. In part, it was the texture of African hair that allowed these cultural practices to develop; as the historian John Thornton has observed, "the tightly spiraled hair of Africans makes it possible to design and shape it in many ways impossible for the straighter hair of Europeans."

There have been a number of examples of European art and sculpture described as similar to modern cornrows, such as plaits, the melon coiffure and sini crenes.