Qiviuq [sg] or qiviut [pl] ( KIV-ee-ət; Inuktitut syllabics: ᕿᕕᐅᖅ; Inuinnaqtun: qiviuq; Inupiaq: qiviu or qiviuq (sometimes spelled qiveut)) is the inner wool of the muskox. In Inuinnaqtun the same word can be used to refer any down such as the down feathers of birds.

The muskox has a two-layered coat, and qiviut refers specifically to the soft underwool beneath the longer outer wool. The muskox sheds this layer of wool each spring. Qiviut is plucked from the coat of the muskox during the moult or gathered from objects the animals have brushed against; unlike sheep, the animals are not sheared. Much of the commercially available qiviut comes from Canada, and is obtained from the pelts of muskoxen after hunts. In Alaska, qiviut is obtained from farmed animals or gathered from the wild during the molt.