Metriacanthosauridae is a family of medium to large allosauroid theropods, part of the broader carnosaur group, that lived from the Middle Jurassic into the Early Cretaceous, roughly 168 to 125 million years ago. Diagnostic features include a robust, deep skull with serrated blade-like teeth, moderately tall neural spines along the back (giving the family its name, meaning "moderately-spined lizards"), pneumatic vertebrae, and powerful hindlimbs built for pursuing prey. Most species reached 6 to 10 meters in length, placing them among the top predators of their ecosystems before the rise of tyrannosaurs and megaraptorans in the Cretaceous.
The family's fossil record is concentrated in East Asia, particularly the Middle to Late Jurassic rock formations of Sichuan, Chongqing, Xinjiang, and Yunnan in China, home to genera such as Yangchuanosaurus and Sinraptor. A notable exception is Metriacanthosaurus itself, the type genus, described from England, indicating the family also had a presence in Jurassic Europe. Metriacanthosauridae represents one of the dominant large predator lineages of Jurassic Asia, filling an ecological role comparable to that of Allosaurus in contemporary North America.