The taxonomy of the Western Indian Ocean species of Acanthopagrus is reviewed. A new species, A. omanensis, is illustrated and described from two specimens. Acanthopagrus vagus (Peters, 1852) is resurrected from the synonymy of Acanthopagrus berda (Forsskål, 1775), redescribed, and compared with A. berda. Acanthopagrus vagus differs from all congeners in the following combination: scale rows between fifth dorsal-fin spine base and lateral line 3; front edge of dorsal scaly area on head with a median W-shaped scaleless area anteriorly; second anal-fin spine longer than third anal-fin spine; ventral edge of first two infraorbitals straight (slightly curved in fish more than 25 cm SL); preopercle flange with 0–6 scales, number increasing with growth, scales obvious on fish more than 20 cm SL; anal fin with pale rays, and a black streak near the base on each inter-radial membrane; molariform teeth well developed on both jaws. Acanthopagrus berda is differentiated from all congeners by the following combination: scale rows between fifth dorsal-fin spine base and lateral line 3; anterior head profile slightly convex, front edge of dorsal scaly area of head convex, with small scales anteriorly; ventral edge of first two infraorbitals with a strongly curved concavity that receives the enlarged tip of the maxilla in fish larger than 13 cm SL; no scales on preopercle flange; second anal-fin spine clearly longer than third anal-fin spine; anal fin almost completely black (no pale rays); molariform teeth well developed, lower jaw teeth rows strongly curved laterally at rear of jaw. Acanthopagrus omanensis, new species, is discernible from all congeners by the following combination: scale rows between fifth dorsal-fin spine base and lateral line 5; front edge of dorsal scaly area on head forming an obtuse angle anteriorly; ventral edge of first two infraorbitals straight; no scales on preopercle flange; second anal-fin spine slender and subequal to third anal-fin spine; dorsal and caudal fins with wide black margins; upper and lower molariform teeth poorly developed. Junior synonyms of A. berda and A. vagus are discussed, with notes on other congeners, including nominal species of Sparidentex, which are sometimes confused with species of Acanthopagrus. A key to species of Acanthopagrus from the Western Indian Ocean is presented.