The Texas horned lizard is one of about 21 North American species of spikey-bodied reptiles called horned lizards, all belonging the genus Phrynosoma. It occurs in south-central regions of the US and northeastern Mexico, as well as several isolated introduced records and populations from Southern United States. Though some populations are stable, severe population declines have occurred in many areas of Texas and Oklahoma. The Texas spiny lizard may be confused for a Texas horned lizard due to its appearance and overlapping habitat.

Phrynosoma, whose members are known as the horned lizards, horny toads, or horntoads, is a genus of North American lizards and the type genus of the family Phrynosomatidae. Their common names refer directly to their horns or to their flattened, rounded bodies, and blunt snouts.