Nichollsia is a genus of plesiosaur from early Cretaceous Canada. It was a small plesiosaur, measuring 2.6–3 m (8.5–9.8 ft) long, 80 kg (180 lb) on average. In 1994, Nichollsia was discovered in one of Syncrude Canada Ltd.'s open-pit oilsand mines, which is close to Fort McMurray.
The specimen found was quite complete, missing only the left forelimb and scapula.
The name, Nichollsia, was then changed to Nichollssaura in 2009 to make the name more generic.