Leptobarbus rubripinna, also known as the Sultan barb, is a species of freshwater ray-finned fish from the carp and minnow family, Cyprinidae which occurs in south-east Asia.

It was until recently considered to be conspecific with Leptobarbus hoevenii but it is now considered to be a separate species, although they share English vernacular names under which both species may appear in the aquarium trade.

One of these names, "mad barb", refers to its behavior when apparently intoxicated after consuming some types of poisonous fruit.

It is a common but never abundant species that occurs in Thailand, Cambodia, Laos, and Vietnam in the drainages of the Mekong, Chao Praya and Mae Klong rivers where it is threatened by damming and deforestation, which destroys the seasonally flooded forest this species often feeds in.

[1] It is a migratory species that moves from the deltas and estuaries upstream to spawn, this occurs in January and February in the Mekong with the fish returning downstream in May and June.