| Named By: | Yaoming Hu, Jin Meng, Chuankui Li & Yuanqing Wang in 2010 |
| Time Period: | Early Cretaceous, 125 Ma |
| Location: | China, LIaoning Province - Yixian Formation |
| Size: | Total size unknown, holotype skull is 25 millimetres long |
| Diet: | Insectivore |
| Fossil(s): | Partial skull |
| Classification: | | Chordata | Mammalia | Eutheria | |
Acristatherium yanensis is an extinct basal eutherian from the Early Cretaceous (early Aptian, about 125 million years ago) Lujiatun Bed of the Yixian Formation. It was described on the basis of a single specimen (holotype) from Beipiao, Liaoning, China, by Yaoming Hu, Jin Meng, Chuankui Li, and Yuanqing Wang in 2010. The specimen comprises a partial skull, 25 mm (0.98 in) long. It appears to possess a vestige of a septomaxilla, a feature only otherwise seen in nonmammalian therapsids.