[3] The snowy sheathbill was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae.

[4] Gmelin based his description on the "white sheath-bill" that had been described and illustrated in 1785 by the English ornithologist John Latham in his A General Synopsis of Birds .

The type locality was designated as the Falkland Islands by Baron Bradford and Charles Chubb in 1912.

[6][7] The snowy sheathbill is now placed in the genus Chionis that was introduced in 1788 by the German naturalist Johann Reinhold Forster.

[11] Sheathbills that are actively hunting for food spend approximately 38% of the day hunting, 20% of the time eating their prey, 23% just resting, 14% doing various comfortable activities, and the final 3% will be towards agonistic behavior.