- Eastern Hellbender (_Cryptobranchus alleganiensis alleganiensis_) - This once abundant species of salamander is now considered to be extirpated from the state, due primarily to habitat loss and pollution.
- Passenger Pigeon (_Ectopistes migratorius_) - This gregarious species was once common in Wisconsin and was part of some of the largest migrations of birds ever documented. It was driven to extinction in the late 18th century due to overhunting and habitat loss.
- Great Auk (_Pinguinus impennis_) - This flightless diving bird was once found in large numbers off the coast of Wisconsin. It was hunted to extinction in the mid-19th century for its feathers and meat.
- Eskimo Curlew (_Numenius borealis_) - This medium-sized sandpiper was once common in Wisconsin and migrated over long distances. It was hunted to extinction in the late 19th century due to overhunting and habitat loss.
- Carolina Parakeet (_Conuropsis carolinensis_) - This colorful bird was once found in flocks in Wisconsin, nesting in old hollow trees. It was hunted to extinction in the early 20th century due to habitat loss and overhunting.
- Eastern Cougar (_Puma concolor couguar_) - This subspecies of cougar was once found in Wisconsin, but it was extirpated in the early 20th century due to hunting and habitat loss.
- Woodland Musk Ox (_Symbos cavifrons_) - This large, shaggy muskrat was once found in Wisconsin and was part of the late Pleistocene megafauna. It went extinct around 10,000 years ago due to climate change and overhunting by humans.
- Pleistocene Bison (_Bison antiquus_) - This massive ancestor of the American bison was the largest known species of bison. It was part of the Pleistocene megafauna and went extinct around 10,000 years ago due to climate change and overhunting.
- Mastodon (_Mammut americanum_) - This iconic Ice Age mammal was common in Wisconsin and is known for its distinctive teeth and long tusks. It went extinct around 10,000 years ago due to climate change and overhunting.
- Woolly Mammoth (_Mammuthus primigenius_) - This iconic Ice Age species was common in Wisconsin and is known for its thick, shaggy coat and long, curved tusks. It went extinct around 10,000 years ago due to climate change and overhunting.