| Named By: | Longman in 1924 | 
| Time Period: | Early Cretaceous, 125-99 Ma | 
| Location: | Australia. Colombia | 
| Size: | Estimated between 9 and 10 meters long. Skull 2.7 meters long | 
| Diet: | Carnivore | 
| Fossil(s): | Two sets of remains and associated individual teeth | 
| Classification: | | Chordata | Reptilia | Sauropterygia | Plesiosauria | Pliosauroidea | Pliosauridae | | 
Kronosaurus ( KRON-o-SAWR-as; meaning "lizard of Kronos") is an extinct genus of short-necked pliosaur. With an estimated length of 9-10.5 metres (30-34 ft), it was among the largest pliosaurs, and is named after the leader of the Greek Titans, Cronus. It lived in the Early Cretaceous Period (Aptian-Albian). Fossil material has been recovered from Queensland in Australia, and from the Paja Formation in Boyaca, Colombia, and assigned to two species.