The Sunjiawan Formation (simplified Chinese: 孙家湾组; traditional Chinese: 孫家灣組; pinyin: Sūnjiāwān Zǔ) is a geological formation in Liaoning, China, with strata possibly dating back to the early Late Cretaceous, specifically the Cenomanian. Dinosaur remains are among the fossils that have been recovered from the formation. It forms part of the same geological sequence as the older and underlying Yixian Formation and Jiufotang Formation. It primarily consists of variegated conglomerates with rare intercalations of thin bedded sandstones, siltstones and mudstones.

Remains of the following dinosaurs have been found in the formation: