Haustellum tweedianum, the Tweed murex, is a species of sea snail, a marine gastropod mollusc in the family Muricidae, the murex snails or rock snails.

Three prominent, rounded varicies per whorl, usually spineless, but occasionally with one or two sharp spines at the base of the varicies and anteriorly on the canal.

Sculptured with gemmate, spiral striae which are occasionally yellowish.

Aperture white, outer lip sharply, minutely dentate.

[citation needed] This marine species can be found off South Queensland and New South Wales, Australia.