The Arctic redpoll or hoary redpoll (Acanthis hornemanni) is a bird species in the finch family Fringillidae. It breeds in tundra birch forest. It has two subspecies, A. h. hornemanni (Greenland or Hornemann's Arctic redpoll) of Greenland and neighbouring parts of Canada, and A. h. exilipes (Coues' Arctic redpoll), which breeds in the tundra of northern North America and the Palearctic. Many birds remain in the far north; some birds migrate short distances south in winter, sometimes travelling with common redpolls.
The genus name Acanthis is from the Ancient Greek akanthis, a name for a small now-unidentifiable bird, and hornemanni commemorates the Danish botanist Jens Wilken Hornemann. The name "arctic redpoll" is used in Europe and "hoary redpoll" in North America.