Neosteneosaurus is a genus of machimosaurid, known from the Middle Jurassic Oxford Clay of the UK, and Marnes de Dives, France.

The type species, N. edwardsi, was originally named as a species of Steneosaurus in 1868,[1] but was moved to its own genus in 2020.

Steneosaurus durobrivensis and Steneosaurus hulkei are considered junior synonyms.

[2] In 2015, it was estimated at more than 7 m (23 ft) in length.

[3] In 2016, this estimate was revised down to 6.6 m (22 ft), but even with such measurement, this animal remains to be the largest known Middle Jurassic crocodylomorph.