Galleonosaurus, which translates to "galleon lizard," is a genus of basal ornithopod dinosaur that hails from the Wonthaggi Formation located in the Gippsland region of Victoria, Australia. The name "Galleonosaurus" is inspired by the resemblance of its upper jaw bone to the upturned hull of a galleon, a type of large sailing ship.

This dinosaur is believed to have been a relatively small, bipedal creature. The holotype representing this genus consists of a hollow jawbone, and as of the current knowledge, no other fossil remains have been associated with Galleonosaurus.