Spinosaurus (meaning "spine lizard") is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian to upper Turonian stages of the Late Cretaceous period, about 99 to 93.5 million years ago.

Spinosaurus was among the largest of all known carnivorous dinosaurs, nearly as large as or even larger than other theropods such as Tyrannosaurus, Giganotosaurus and Carcharodontosaurus.

Estimates published in 2005, 2007, and 2008 suggested that it was between 12.6 to 18 meters (41 to 59 ft) in length and 7 to 20.9 metric tons (7.7 to 23.0 short tons) in weight.