| Megawhaitsia Temporal range:
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| Illustration of the holotype maxilla showing possible venom ducts | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Synapsida |
| Clade: | Therapsida |
| Clade: | †Therocephalia |
| Family: | †Whaitsiidae |
| Genus: | †Megawhaitsia Ivakhnenko, 2008 |
| Type species | |
| †Megawhaitsia patrichae | |
Megawhaitsia is an extinct genus of large therocephalian therapsids who lived during the Late Permian (Wuchiapingian) in what is now Eastern Europe. The only known species is M. patrichae, described in 2008 from several fossils discovered in various oblasts of European Russia. The fossils are representative of a large animal whose skull size is estimated to be 40–50 cm (16–20 in) long.
The most notable feature of Megawhaitsia is that it has a maxilla with canals directly connected to the tooth root of the canines. Based on the characteristics present in the related genus Euchambersia, Russian paleontologist Mikhail Ivakhnenko raises the possibility that the animal may have had a venom gland. If it is true, then it would then be one of the oldest tetrapods known to have this attribute. Subsequent studies have challenged this proposition.
The imposing size of Megawhaitsia and its position as an apex predator could be linked to the disappearance or absence of large gorgonopsians at the end of the Late Permian in certain regions of present-day European Russia. Megawhaitsia could thus have occupied the ecological niches previously occupied by the gorgonopsians.