‘Barbus’ serengetiensis is described from rivers in Serengeti National Park, Tanzania, East Africa. The rivers are part of the Grumeti River drainage, itself part of the Lake Victoria basin. ‘Barbus’ serengetiensis is a small species diagnosed by the following combination of characters: radiately striate scales having fewer than 15 striae; dorsal fin with seven branched rays; dorsal fin origin posterior to pelvic fin origin; a single pair of short barbels; a short snout with a terminal, anterodorsally directed mouth; incomplete lateral line; 32–36 scales in the lateral line series; 16 scales around the caudal peduncle; no pelvic axillary scale; and 10–12 olfactory lamellae. It is unusual among African ‘Barbus’ in having high scale counts combined with a last unbranched dorsal ray that is segmented and flexible.