Thyrsitoides jordanus sp. nov. is very closely related to Thyrsitoides marleyi Fowler, 1929 (from Western Indian Ocean). Contrasting features are: a lower anal and second dorsal fin count, number of teeth, presence of fleshy lateral keels on caudal base, an asymmetrical termination of the upper branch of the lateral line, presence of ribbings on both sides of lower branch of lateral line, a more spinescent gill arch and pale ventral fins. T. jordanus is probably a species endemic to the Red Sea developed from its relative in the Indian Ocean.