Sundadanio axelrodi is a danionin in the family Cyprinidae. Originally described as a rasbora, Rasbora axelrodi, this tiny species was later deemed to be more closely related to the danios but not enough to be moved into the genus Danio. Sundadanio axelrodi reaches a maximum size of 1.7 cm. Sundadanio was considered monotypic until the genus was reassessed by Conway, Kottelat and Tan in 2011.