Small vesper mouse
Calomys laucha
- Least concern
- Card rarity: Common
- Mammals

The small vesper mouse is a rodent species from South America. It is found in Argentina, Bolivia, Brazil, Paraguay and Uruguay. It is one of the hosts of hantavirus, causing hantavirus pulmonary syndrome.
Classification
- Class
- Mammalia
- Order
- Rodentia
- Family
- Cricetidae
- Genus
- Calomys