Xinjiangtitan (Chinese: 新疆巨龙; pinyin: Xīnjiāngjùlóng) is an extinct genus of mamenchisaurid sauropod that lived during the Middle Jurassic of what is now Xinjiang, northwestern China.

Its type and only species is Xinjiangtitan shanshanesis (Chinese: 鄯善新疆巨龙; pinyin: Shànshàn Xīnjiāngjùlóng), known from a single incomplete skeleton recovered from the Qiketai Formation.

In 2013, before the specimen had been fully excavated, Wu Wen-hao, Zhou Chang-fu, Oliver Wings, Toru Sekiha and Dong Zhiming described it as a new genus and species, Xinjiangtitan shanshanesis.

[5][6] Xinjiangtitan was diagnosed based on the following traits: the presence of a ventral keel on the penultimate cervical centrum that forms a small semicircular process under the distal articular facet; both cervical vertebrae are relatively elongated; the sacricostal yoke except the first sacral rib; and an extremely robust femur.

Xinjiangtitan shares several derived characters with diplodocids, including prominent ambiens process of pubis, relatively short hind limb and fourth trochanter on the femur that is caudomedially developed.