Sceloporus occidentalis is a species of lizard commonly known as a Western fence lizard, blue-belly, or swift. The Western fence lizard is native to the western United States and is often seen basking on rocks or woodpiles. Western fence lizards are called blue-belly due to their characteristic blue throat and belly. The lizard's scientific name, Sceloporus occidentalis, comes from the Greek words for "leg" (skelos) and "to look" (poros) because of the lizard's distinctive legs and its tendency to look around rapidly. Other synonyms for Sceloporus occidentalis include Swift lizard, Prairie lizard, and Common fence lizard. Regardless of its name, Sceloporus occidentalis is an important species in the ecological landscape of the western United States.