The Arctic redpoll (Acanthis hornemanni), known in North America as the hoary redpoll, 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's Arctic redpoll), which breeds in the tundra of northern North America and Eurasia. Many birds remain in the far north; some birds migrate short distances south in winter, sometimes travelling with common redpolls. The binomial commemorates the Danish botanist Jens Wilken Hornemann.