This is an overview of the suborder Serpentes, its two infraorders (subdivisions) and the families they contain.

There are two infraorders of living snakes: Alethinophidia and Scolecophidia.

This separation is based primarily on morphological characteristics between family groups; however, more recently, the comparison of mitochondrial DNA has played its part.

As with most taxonomic classifications, there are many different interpretations of the evolutionary relationships.

For instance, many sources classify Boidae and Pythonidae as the same family, or keep others, such as Elapidae and Hydrophiidae, separate for practical reasons despite their extremely close relationship.