| Named By: | Friedrich von Huene in 1922 |
| Time Period: | Late Jurassic, Kimmeridgian-Tithonian |
| Location: | England - Kimmeridge Clay Formation, Madagascar?, Norway, Spitsbergen - Agardhfjellet Formation, and Russia |
| Size: | Depending upon the species, between 2.5 and 5 meters long |
| Diet: | Piscivore |
| Fossil(s): | Several individuals, though often of partial remains |
| Classification: | | Chordata | Reptilia | Ichthyosauria | Ophthalmosauridae | Platypterygiinae | |
| Also known as: | | Brachypterygius zhuralevi | Grendelius mordax | Ichthyosaurus extremus | Otschevia pseudoscythius | Brachypterygius mordax | |
Brachypterygius (meaning ''wide wing/paddle'' in Greek) is an extinct genus of platypterygiine ophthalmosaurid ichthyosaur known from the Late Jurassic of England. The type species was originally described and named as Ichthyosaurus extremus by Boulenger in 1904. Brachypterygius was named by Huene in 1922 for the width and shortness of the forepaddle, and the type species is therefore Brachypterygius extremus. The holotype of B. extremus was originally thought to be from the Lias Group of Bath, United Kingdom, but other specimens suggest it more likely came from the Kimmeridgian Kimmeridge Clay (Late Jurassic) of Kimmeridge Bay, Dorset, UK.