Etheostoma flabellare has long been recognized as a geographically variable, polytypic species that contains undescribed species-level diversity. As the first phase of a long-term study, morphological comparisons were made on one historically recognized subspecies, E. f. brevispinum, to examine variation and determine its distribution and taxonomic status within the E. flabellare complex. Examination and analyses of meristic, morphometric, and pigmentation variables from nine river drainages (Atlantic Slope and Mississippi River Basin) revealed that Etheostoma brevispinum, the Carolina Fantail Darter, is diagnosable based on a combination of characteristics and is restricted to the Savannah, Santee, and Yadkin (upper Pee Dee River) rivers of North Carolina, South Carolina, and Virginia. Data do not support recognition of New and Roanoke River populations of E. flabellare as intergrade zones between E. brevispinum and E. flabellare as previously suggested. A potential contact zone between E. brevispinum and other forms of the E. flabellare complex was identified in the Pee Dee River; however, no intermediate populations suggestive of an intergrade zone were identified.