| Named By: | Lewis Camp in 1936 |
| Time Period: | Early Jurassic, 183 Ma |
| Location: | USA, Arizona, Tsegi Canyon - Navajo Sandstone Formation |
| Size: | Estimate about 1 meter long, but since this was a sub-adult, full size would have been a little larger |
| Diet: | Insectivore/Carnivore |
| Fossil(s): | Partial post cranial remains of a sub adult |
| Classification: | | Chordata | Reptilia | Dinosauria | Saurischia | Theropoda | Coelophysidae | |
Segisaurus (meaning "Segi canyon lizard") is a genus of small coelophysoid theropod dinosaur, that measured approximately 1 metre (3.3 feet) in length. The only known specimen was discovered in early Jurassic strata in Tsegi Canyon, Arizona, for which it was named. Segisaurus is the only dinosaur to have ever been excavated from the area.