Hyenas, or hyaenas (from Ancient Greek ὕαινα, hýaina), are feliform carnivoran mammals belonging to the family Hyaenidae . With just four extant species (each in its own genus), it is the fifth-smallest family in the Carnivora and one of the smallest in the class Mammalia. Despite their low diversity, hyenas are unique and vital components of most African ecosystems.

Although phylogenetically closer to felines and viverrids, as part of suborder Feliformia, hyenas are behaviourally and morphologically similar to canids in several elements due to convergent evolution: both hyenas and canines are non-arboreal, cursorial hunters that catch prey with their teeth rather than claws. Both eat food quickly and may store it, and their calloused feet with large, blunt, nonretractable claws are adapted for running and making sharp turns. However, hyenas' grooming, scent marking, defecation habits, mating and parental behavior are consistent with the behavior of other feliforms.

Hyenas feature prominently in the folklore and mythology of human cultures that live alongside them. Hyenas are commonly viewed as frightening and worthy of contempt. In some cultures, hyenas are thought to influence people's spirits, rob graves, and steal livestock and children. Other cultures associate them with witchcraft, using their body parts in traditional medicine.