Tectus fenestratus, common name the fenestrate top shell or the latticed top shell, is a species of sea snail, a marine gastropod mollusk in the family Tegulidae.

The entire surface above the periphery is covered with fine oblique wrinkles, which are more or less beaded by a few (3 to 5) revolving lirae.

The outer lirae are crenulated by fine radiating wrinkles which are continued a short distance inward from the periphery.

This species is a variable form, which, however may be readily recognized by the sutural knobs and secondary sculpture of fine wrinkles above, and by the crenulated or beaded line around the outer edge of the base.

[5] This marine species occurs in the Central and West Pacific Ocean, Indo-China, Indo-Malaysia, and off Papua New Guinea, New Caledonia and Australia (Northern Territory, Queensland, Western Australia).