A new species of snapper of the genus Lutjanus is described from the Indo-western Pacific region, and the related species with which it frequently has been confused, Lutjanus madras (Valenciennes 1831), is redescribed. Lutjanus xanthopinnis n. sp. is described from 11 specimens, 56–192 mm SL, from Kagoshima in southern Japan, Taiwan, Indonesia, and Sri Lanka. It differs from L. madras in meristics, color, and squamation of the preopercular flange. The new species is distinguished by several embedded scales on the preopercular flange, 4 or 5 scale rows on the cheek, and mostly uniform thin yellow to brownish stripes on the body on adults, missing the well-contrasted and much broader mid-lateral stripe characteristic of L. madras. In contrast, L. madras lacks scales on the preopercular flange, has 7 or 8 scale rows on the cheek, and has a broad (up to pupil diameter), wellcontrasted yellow to brownish stripe along the lateral midline. Comparison of the barcode mitochondrial COI genetic marker reveals a 6.4% minimum interspecific divergence (uncorrected pairwise) between the two species. We also conclude that L. madras, formerly considered to be widely distributed in the Indo-western Pacific region, is actually restricted to the Indian Ocean (Zanzibar, Seychelles, Oman, Sri Lanka, and southern India), with the two species apparently sympatric in Sri Lanka. The yellow-lined snapper complex of the Indo-Pacific is clarified, including morphological and marking differences, genetic relationships, and species distributions.