Tectarius antonii is a species of sea snail, a marine gastropod mollusc in the family Littorinidae, the winkles or periwinkles.

[1] The maximum recorded shell length is 21 mm.

[2] This species occurs in the Gulf of Mexico, the Caribbean Sea and the Lesser Antilles.

Minimum recorded depth is -2 m.[2] Maximum recorded depth is 0 m.[2]

This Littorinidae-related article is a stub.