Cochineal (Coccus cacti or Dactylopius coccus ) is an insect in the order of Homoptera, found in Mexico and Central and South America. The beetles live on various cactus plants and are parasitic. They feed on the juices from the cactus leaves.

Cochineal is also the name of the crimson or carmine colour dye, made from the dried bodies of the females (in the case of "cochineal") or the crushed eggs (in the case of "cochineal extract"). The coloring comes from carminic acid. Cochineal is used as a fabric and cosmetics dye and as a natural food coloring, as well as for oil paints and watercolours. An unknown percentage of people have been found to have allergies to carmine, ranging from mild cases of hives, to anaphylactic shock. When used in foods, the dye may be labelled as E120 on packaging labels.

The use of cochineal and carmine as dyes dates back to pre-Hispanic Mexico where it is believed the Mixtec Indians extracted the dye for use on fabrics.

Cochineals are soft-bodied, flat, oval shaped insects that cluster on plants and suck out their juices. There are at least 2,000 types of scales. Female cochineals are red and feed on prickly pear cactus. They also secrete a waxy, white material over their bodies for protection. This secretion looks like spit on a plant. The feeding of the female cochineal often causes damage and sometimes kills the host cactus plant. Adult males have wings, are tiny and cannot feed at all. They only live long enough to fertilize the eggs. Immature males can feed for a short time.