Linaria kavirensis Hamdi & Assadi (Scrophulariaceae) is described and illustrated as a new species from the central desert and eastern provinces of Iran. It belongs in sect. Supinae and is compared with the morphologically close L. simplex, from which it differs by having filiform vs. linear leaves, shorter bracts (1.5–2 mm vs. 2 × 0.5–0.7 mm), shorter corolla (5–6 mm vs. 7–7.5 mm), shorter spur (1.5–1.7 mm vs. 2.5–3 mm), smaller capsules (3–3.5 mm vs. 4–4.5 mm), and smaller seeds with smooth vs. tuberculate surface. In addition, L. kavirensis is compared with L. arvensis and L. micrantha by means of scanning electron micrographs of seed and capsule surfaces.