Ferganasaurus is a genus of sauropod dinosaur belonging to the group Mamenchisauridae. It lived during the Late Jurassic period, approximately 165 to 163 million years ago. The first fossils of Ferganasaurus were unearthed in the Fergana Basin of present-day Kyrgyzstan.

Ferganasaurus was a colossal sauropod. While exact measurements are difficult to ascertain due to incomplete remains, it is estimated to have reached lengths of up to 70 feet (21 meters) or more. There is no cranial fossils to be found and not much is known about this dinosaur.