| Named By: | Wiffen & Moisley in 1986 |
| Time Period: | Late Cretaceous, 78 Ma |
| Location: | New Zealand - Tahora Formation |
| Size: | Estimated at 8 meters long |
| Diet: | Piscivore/Carnivore |
| Fossil(s): | Based upon an almost complete skull, mandible (lower jaw), and cervical (neck) vertebra. Partial post cranial remains have been attributed to the genus |
| Classification: | | Reptilia | Sauropterygia | Plesiosauria | Elasmosauridae | |
Tuarangisaurus (Maori tuarangi "ancient" + Greek sauros "lizard") is an extinct genus of elasmosaurid known from New Zealand. The type and only known species is T. keyesi, named by Wiffen and Moisley in 1986.