The weedy sea dragon or common sea dragon (Phyllopteryx taeniolatus) is a marine fish related to the seahorse. It is the only member of the genus Phyllopteryx. It is found in water 3 to 50 m deep around the southern coastline of Australia, approximately between Port Stephens, New South Wales and Geraldton, Western Australia, as well as around Tasmania. Weedy sea dragons are named for the weed-like projections on their bodies that camouflage them as they move among the seaweed beds where they are usually found.

Weedy sea dragons can reach 45 cm in length. They feed on tiny crustaceans and other zooplankton, which are sucked into the end of their tube-like snout.