Stethojulis trilineata is a small species of wrasse which can grow to a total length of 15 centimetres (5.9 in).

Fish in the terminal phase, males, show three thin, pale pink stripes running along the body with a fourth stripe starting on the head reaching to above the pectoral fin.

[2] Stethojulis trilineata is widespread in the Indo-West Pacific where it is found from Maldives east to Samoa and Palau, north to Tokara Island of Japan and south to Montague Island of Australia.

[1] Stethojulis trilineata is found on reefs exposed to currents which have clear water.

Spawning occurs at various times of the day and does not appear to be influenced by either lunar or tidal effects.