The St. Lucia threadsnake (Tetracheilostoma breuili) is a species of blind snake in the family Leptotyphlopidae.

The specific name, breuili, is in honor of French herpetologist Michel Breuil.

[4] The preferred natural habitat of T. breuili is forest, at altitudes of 40–60 m (130–200 ft).

[1] T. breuili can reach a total length (including tail) of 119 mm (4.7 in).

It is dark brown with two yellowish lateral stripes, like the closely related L. bilineatus (Martinique) and L. carlae (Barbados).