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Walgettosuchus (meaning "Walgett crocodile") is a dubious genus of theropod dinosaur. In 1905 an opalised vertebra of a theropod dinosaur was found near Wollaston, at Lightning Ridge in New South Wales. The fossil was sent to the British Museum of Natural History and was reported in 1910 by Arthur Smith Woodward.

In 1932 the type species Walgettosuchus woodwardi was named by Friedrich von Huene, based on this vertebra. The generic name is derived from the town of Walgett and Sohos, the Greek name of the Egyptian crocodile god Sobek. During the 1930s Von Huene tended to form dinosaur names with the ending ~suchus instead of ~saurus because of the closer relationship to crocodiles than to lizards. The specific name honours Woodward.

Being a single‭ ‬opalised‭ ‬vertebrae that it is known from has been criticised as not being diagnostic enough to establish a specific genus.‭ ‬As such, Walgettosuchus is generally regarded as being what is called a nomen dubium,‭ ‬a genus that cannot be definitively confirmed to exist.‭ ‬However, many other Australian dinosaur genera have been named from single bones including Ozraptor,‭ Rapator and Kakuru,‭ ‬the latter two also having opalised fossils.

The holotype, BMNH R3717, was found in the Albian-age Lower Cretaceous Griman Creek Formation. It consists of a 63mm long incomplete amphicoelous (concave surfaces for articulation on the anterior and posterior faces) caudal vertebral centrum. For unknown reasons, its discoverer believed it had elongate prezygapophyses. He also suggested that if more material was known, it could prove to be synonymous with other Lightning Ridge "coelurosaurs" (i.e. Rapator; coelurosaur in the outdated sense of any small theropod).

In his 1990 review, Ralph Molnar noted that the type cannot be distinguished from tail vertebrae from ornithomimids or allosaurids, and considered it to be an indeterminate theropod and a nomen dubium.