Conus sydneyensis 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 not be handled at all, except by qualified federal animal control personnel.
Length of the shell varies between 21mm and 35mm, weighs medium with slightly convex or straight sides.
