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

[3] It is endemic to Sarawak, Malaysian Borneo, and known from the Rajang and Sarawak River drainages.

It lives in coastal peat swamp forests.

[1] Sundadanio margarition reaches a maximum size of 1.9 cm (0.75 in) standard length.

[4]