| Named By: | M. J. Polcyn & G. L. Bell Jr in 2005 |
| Time Period: | Late Cretaceous, Turonian |
| Location: | USA, Texas - Arcadia Park Shale and Kamp Ranch Limestone |
| Size: | Uncertain |
| Diet: | Carnivore |
| Fossil(s): | Skull as well as additional fragmentary remains |
| Classification: | | Chordata | Reptilia | Squamata | Mosasauridae | Russellosaurinae | |
Russellosaurus is an extinct genus of tethysaurine mosasauroid from the Late Cretaceous of North America. The genus was described from a skull discovered in an exposure of the Arcadia Park Shale (lower Middle Turonian) at Cedar Hill, Dallas County in south-central Texas, United States. The skull (SMU 73056, Shuler Museum of Paleontology, Southern Methodist University) was found in 1992 by a member of the Dallas Paleontological Society, who then donated to the museum. Other fragmentary specimens of Russelosaurus have been recovered from the slightly older Kamp Ranch Limestone at two other localities in the Dallas area.