Science magazines
- Owens Tui Chub
- Oyster Mussel
- Ozark Big-eared Bat
- Ozark Cavefish
- Pacific Pocket Mouse
- Pahranagat Roundtail Chub
- Pahrump Poolfish
- Painted Rocksnail
- Painted Snake Coiled Forest Snail
- Paiute Cutthroat Trout
- Pale Lilliput Pearlymussel
- Palezone Shiner
- Palila
- Pallid Manzanita
- Pallid Sturgeon
- Palma de Manaca
- Palmate-bracted Bird's-beak
- Palo Colorado
- Palo de Jazmin
- Palo de Nigua