A species of Trimma with a vertically-sided, ‘U’-shaped interorbital trench and well developed postorbital trench, scales centred on the predorsal midline usually absent (although there may be 1–3 scales anteriorly in the midline, with a narrowly triangular naked area in front of the first dorsal spine); second dorsal spine elongated in adults (>20 mm SL), and may reach posteriorly to the dorsal procurrent caudal fin rays; third spine somewhat elongated, often extending beyond the spine of the second dorsal fin; usually 10 dorsal, 9 anal and 17–19 pectoral-fin rays, the latter with 5–12 branched rays at the middle of the fin, fifth pelvic ray usually branched once and about half the length of the fourth (47–64%); 18–20 total gill rakers on the first gill arch; and bony interorbital width less than half pupil-diameter. When freshly collected, this species is immediately distinguishable from all other described species of Trimma by the broad oblique yellow stripe across the cheek (Ref. 100726).