A Slavic dragon is any dragon in Slavic mythology, including the Polish żmij, Russian zmei (or zmey; змей), Ukrainian zmiy (змій), and its counterparts in other Slavic cultures (See § Forms below). The physiognomy resembles a combination of the classical dragon and a snake (as a winged serpent), less often depicted with two legs and/or more than one head. Similar representations include the Aztec Quetzalcoatl (Feathered Serpent) or Caduceus (Sumerian symbol of the god Enki borrowed into Greek mythology).

The Romanian zmeu could also be deemed a "Slavic" dragon, but a non-cognate etymology has been proposed.

A zmei may be beast-like or human-like (assuming dragon form in air, human form on ground), sometimes wooing women, but often plays the role of chief antagonist in Russian literature. In the Balkans, the zmei type is overall regarded as benevolent, as opposed to malevolent dragons known variously as lamia, ala or hala, or aždaja.

The Polish smok (e.g. Wawel Dragon of Kraków) or the Ukrainian or Belarusian smok (смок), tsmok (цмок), can also be included. In some Slavic traditions smok is an ordinary snake which may turn into a dragon with age.

Some of the common motifs concerning Slavic dragons include their identification as masters of weather or water source; that they start life as snakes; and that both the male and female can be romantically involved with humans.