Titanosaurus ('titanic reptile') is a genus of sauropod dinosaur.

Titanosaurus was 9-12 m (30-40 ft) long and weighed about 13 tons. Titanosaurus has traditionally been treated as a "wastebin" taxon for poorly preserved sauropod remains that demonstrate a distinctive vertebrae anatomy. The original Titanosaurs remains consist only of limb bones and a few vertebrae that have these characteristics. However, discoveries of more and better-preserved titanosaur species have shown that these once distinctive features are infact widespread across many genera. Therefore, Titanosaurus itself is considered a nomen dubium ("dubious name") by most paleontologists, since the original Titanosaurus specimens cannot be distinguished from those of related animals.

The most well-known species of Titanosaurus, "Titanosaurus" colberti, has been renamed Isisaurus.

Cretaceous dinosaurs | South American dinosaurs | Titanosaurs