The arrow darter (Etheostoma sagitta) is a species of darter endemic to the southeastern United States where it is found only in the upper Kentucky and upper Cumberland River drainages in Kentucky and Tennessee. This species inhabits pools and rocky riffles of headwaters up to small streams. Diet consists of mayfly nymphs, blackfly, stonefly, beetle, and caddisfly larvae. This species can reach a length of 12 centimetres (4.7 in) TL.