| Named By: | G. L. Bell Jr & M. J. Polcyn in 2005 |
| Time Period: | 92 Ma Late Cretaceous |
| Location: | USA, Texas, Dallas County - Kamp Ranch Limestone |
| Size: | Up to 1 meter long |
| Diet: | Carnivore |
| Fossil(s): | 2 partial specimens, together represented by a partial skull and disarticulated post cranial remains |
| Classification: | | Chordata | Reptilia | Squamata | Mosasauridae | Mosasaurinae | |
Dallasaurus ("Dallas lizard") is a basal mosasauroid from the Upper Cretaceous of North America. Along with Russellosaurus, Dallasaurus is one of the two oldest mosasauroid taxa currently known from North America. This small semi-aquatic lizard measured less than a meter in length, compared to such gigantic derived mosasaurs as Tylosaurus and Mosasaurus, each exceeding 14 meters.