Sundadanio atomus is a species of freshwater ray-finned fish belonging to the family Sundadanionidae, the tiny danios.

[3] It is endemic to Singkep, off Sumatra (Indonesia).

It lives in peat swamp forests.

[1] Sundadanio atomus reaches a maximum size of 1.6 cm (0.63 in) standard length.

[4]