Four new species of Gentianella Moench are described from Peru. Gentianella iberidea J. S. Pringle differs from G. graminea (Kunth) Fabris in its obtuse, non-arcuate leaves. Gentianella sagasteguii J. S. Pringle differs from similar species in its combination of linear-elliptic leaves, narrowly triangular calyx lobes, and lilac, widely campanulate to subrotate corollas with the lobes (1.1–)1.7–2× as long as the tube. Gentianella smithii J. S. Pringle differs from G. paludicola (Gilg) J. S. Pringle and G. roseolilacina (Gilg) J. S. Pringle in its perennial habit and blue corollas. Gentianella uberula J. S. Pringle differs from G. sagasteguii in its wider leaves and less deeply lobed corollas.