Northwestern Deer Mouse
Peromyscus keeni
- Least concern
- Card rarity: Common
- Mammals

The northwestern deer mouse, northwestern deermouse, or Keen's mouse is a species of rodent in the family Cricetidae. It is a species of the genus Peromyscus, a closely related group of New World mice often called "deermice".
Classification
- Class
- Mammalia
- Order
- Rodentia
- Family
- Cricetidae
- Genus
- Peromyscus