The long-tailed dwarf hamster (Cricetulus longicaudatus) is a species of rodent in the family Cricetidae.

The long-tailed dwarf hamster has a head and body length of between 85 and 135 mm (3.35 and 5.31 in) and a tail at least a third as long as this.

There is a sharp dividing line at the side of the body separating the dorsal and ventral colourings.

It is especially abundant in piedmont semidesert, a type of desert grassland with mixed shrubs and succulent plants, or savannah with scattered xeromorphic trees.

It constructs shallow tunnels and burrows under boulders, creating storage chambers where excess food is stored for winter use.