A new species of American sole, captured in freshwater tributaries of the Río San Juan and Río Condoto, near Andagoya, Colombia, is described from four specimens collected by H. G. F. Spurrell around 1913. These fish were deposited in the fish collection of the British Museum (Natural History) and originally identified as Solea panamensis Steindachner, 1876. In the 1960s, Carl L. Hubbs and John A. Bollinger re-examined the specimens and determined that they represented an undescribed species, as indicated by labels placed in jars containing these specimens and through correspondence with staff at the British Museum. However, no formal description of this nominal species was published and its taxonomic status remained unclear. Our re-examination of these specimens and comparisons with all other described species of Trinectes support the conclusions of Hubbs and Bollinger that they are not Solea panamensis, now considered a junior subjective synonym of Trinectes fonsecensis (Günther, 1862), and that they represent an undescribed species. Formal description of the new species, Trinectes hubbsbollinger, named in recognition of the initial discoverers, is provided herein. Trinectes hubbsbollinger is distinguished from its congeners by the combination of 7–8 lightly pigmented, transverse chromatophore lines on the ocular side of the body, ocular-side lower lip with short fimbriae with few branches, few or no cirri on the scaleless area surrounding the ocular-side anterior naris, and absence of pectoral-fin rays.