Alcyna subangulata is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.

The minute, rather solid, narrowly perforate shell has an ovate-turbinate shape.

The body whorl is obtusely biangular with about four low spiral cords above the upper angle, two and a very weak third between the angles.

The outer lip is thickened externally with a swelling or varix.

[2][3] This marine species occurs off the Seychelles, Mauritius, Réunion and Hawaii.