The Kodiak bear (Ursus arctos middendorffi), also known as the Kodiak brown bear or the Alaskan grizzly bear or American brown bear, occupies the islands of the Kodiak Archipelago in South-Western Alaska. Its name in the Alutiiq language is Taquka-aq. It is the largest subspecies of brown bear.

Taxonomist C.H. Merriam was the first to recognize Kodiak bears as unique and he named the species "Ursus middendorffi" in honor of the celebrated Baltic naturalist Dr. A. Th. von Middendorff. Subsequent taxonomic revisions merged most North American brown bears into a single subspecies (Ursus arctos horribilis), but Kodiak bears are still considered to be a unique subspecies (Ursus arctos middendorffi). Recent investigations of genetic samples from bears on Kodiak have shown that they are closely related to brown bears on the Alaska Peninsula and Kamchatka, Russia. It appears that Kodiak bears have been genetically isolated since at least the last ice age (10,000 to 12,000 years ago) and there is very little genetic diversity within the population. Although the current population is healthy and productive, and has shown no overt adverse signs of inbreeding, it may be more susceptible to new diseases or parasites than other more diverse brown bear populations