Leptobarbus hosii, the Sayan Barb, also locally called as Piam and Temopong, is a species of ray-finned fish in the genus Leptobarbus from freshwater habitats in northern Borneo in southeast Asia.

However, a previously unknown population has been recorded in West Kalimantan.

[2] Named in honor of Charles Hose (1863–1929), British colonial administrator in Borneo, zoologist and ethnologist, who collected the type specimen.

It does not have a black lateral line running along its body, unlike L. melanotaenia and L. rubripinna.

Maxing out at 8.5 cm,[5] it is possibly the smallest member of its genus.