Conus thalassiarchus, common name the bough cone, is a species of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails and their allies. Like all species within the genus Conus, these snails are predatory and venomous. They are capable of stinging humans, therefore live ones should be handled carefully or not at all.

Description The size of the shell varies between 35 mm and 115 mm. The spire is depressed and nearly smooth, with a sharp angle. The color of the shell is white, longitudinally and angularly reticulated with chestnut lines, chocolate-tinted at the base. It shows sometimes an irregular central white band covered by revolving lines of spots, and occasionally with yellowish bands above and below the latter and similarly spotted.

Distribution This marine species occurs off the Southern Philippines.