A new endemic species of gymnophthalmid lizard of the genus Riama is described from the Cordillera Occidental of northern Colombia. The new species differs from all known Riama by pholidosis, hemipenial morphology, and color pattern. The four known endemic Colombian species, Riama columbiana, Riama laevis, Riama stellae, and Riama striata, occur in different montane forests and are not known to be sympatric with the new species. The new species most resembles R. laevis from the Cordillera Occidental of the Colombian Andes, but it differs in having 15 longitudinal scale rows, 21–23 transverse scale rows in males and 22 in females, and limbs that do not overlap or just touch when adpressed against the body.