Pteropurpura trialata, the three-winged murex, is a medium-sized species of predatory sea snail, a marine gastropod mollusk in the family Muricidae, the rock snails or murex snails.

It is native to the eastern Pacific Ocean.

[2] It is fusiform and fairly thick, with a spire angle of 40-42°.

Each whorl has three elaborately sculptured varices (thickened protruding ridges) with nine to twelve fluted cords extending onto the varices.

[3] The three-winged murex occurs in the semi-tropical eastern Pacific Ocean, its range extending from northern California, through Baja California to Mexico.