Diadophis punctatus, commonly known as the ring-necked snake or ringneck snake, is a rather small, harmless species of colubrid snake found throughout much of the United States, as well as south in Central Mexico and as far north as Quebec, Canada. Ring-necked snakes are generally fossorial and somewhat secretive, by nature, and, as a nocturnal species, are rarely seen during the daytime. These snakes are believed to be fairly abundant throughout most of their range, though no scientific evaluation supports this hypothesis. Scientific research is lacking for the species, despite their apparently common status, and more in-depth investigations are greatly needed. It is the only species within the genus Diadophis and, currently, 14 subspecies are identified, though many herpetologists question the morphologically-based classifications.

Colubridae is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. Colubrid snakes are found on every continent except Antarctica.