Hatt's Vesper Rat
Otonyctomys hatti
- Least concern
- Card rarity: Common
- Mammals

Hatt's vesper rat, also known as Hatt's vesper mouse or Yucatán vesper rat, is a species of rodent in the family Cricetidae. It is the only species in the genus Otonyctomys. It is named for its discoverer, Robert T. Hatt.
Classification
- Class
- Mammalia
- Order
- Rodentia
- Family
- Cricetidae
- Genus
- Otonyctomys