The marbled darter (Etheostoma marmorpinnum) is a species of darter endemic to the eastern United States. It occurs in Tennessee in the Little River drainage and formerly occurred in the Holston River where it is now extirpated, not having been collected there since the completion of the South Fork Holston Dam. This species can reach a length of 4.1 centimetres (1.6 in) SL.