| Named By: | Michel Laurin in 1991 |
| Time Period: | Early Permian |
| Location: | USA, Texas - Archer City Formation |
| Size: | Unavailable |
| Diet: | Carnivore |
| Fossil(s): | Partial post cranial skeleton as well as a partial skull and jaws |
| Classification: | | Chordata | Synapsida | Eupelycosauria | Varanopidae | |
Apsisaurus is an extinct genus of Early Permian varanopid synapsid known from Texas of the United States. It was first named by Michel Laurin in 1991 and the type species is Apsisaurus witteri. Apsisaurus witteri is known from the holotype MCZ 1474, a three-dimensionally preserved partial skeleton including an incomplete skull and mandibles. The skull roof of Archeria is also articulated to the postcranial skeleton. It was collected in the Archer City Bonebed 1 site, from the Archer City Formation of the Wichita Group, dating to the Early Permian epoch. Apsisaurus was formerly assigned as an "eosuchian" diapsid. In 2010, it was redescribed by Robert R. Reisz, Michel Laurin and David Marjanovic; their phylogenetic analysis found it to be a basal varanopid synapsid.
Below is a simplified version of the cladogram found by Reisz, Laurin and Marjanovic, 2010.