腔骨龙属（学名：Coelophysis）又名虚形龙，是北美洲的小型、肉食性、双足恐龙，也是已知最早的恐龙之一。牠首先出现于三叠纪晚期的诺利阶。

腔骨龙是最早发现几副完整骨骼的恐龙。模式种鲍氏腔骨龙（C. bauri）是轻盈的恐龙，约有2-3米长，臀部高于1米高。牠的属名是来自古希腊文的「κοιλος」（意即空心）及「φυσις」（意即形态），是取自牠那空心的四肢骨头。

腔骨龙的体型亦比艾雷拉龙及始盗龙更为衍化。腔骨龙的头部具有着大型洞孔，可帮助减轻头颅骨的重量，而洞孔间的狭窄骨头可以保持头颅骨的结构完整性。长颈部则呈S形。

Coelophysis (/ˌsɛloʊˈfaɪsᵻs, ˌsiː-/; pron.:SEL-oh-FY-sis or SEE-low-FY-sis) is an extinct genus of coelophysid theropod dinosaur that lived approximately 203 to 196 million years ago during the latter part of the Triassic Period in what is now the southwestern United States. It was a small, slenderly-built, ground-dwelling, bipedal carnivore, that could grow up to 3 m (9.8 ft) long. Coelophysis is one of the earliest known dinosaur genera. Scattered material representing similar animals has been found worldwide in some Late Triassic and Early Jurassic formations. The type species C. bauri, originally given to the genus Coelurus by Edward Drinker Cope in 1887, was described by the latter in 1889. The names Longosaurus and Rioarribasaurus are synonymous with Coelophysis. Another dinosaur genus, Megapnosaurus, has also been considered to be a synonym. This primitive theropod is notable for being one of the most specimen-rich dinosaur genera.