In Norse mythology, Duergar or Dvergar is the name of Dwarfs.

In the Dungeons & Dragons fantasy role-playing game the duergar are a race of cruel and evil dwarves. They are best referred to as the dwarvish equivalent of the drow. Duergar are stoic and hard-working, toiling under the gaze of Laguduer , their strict and unforgiving deity. They have a deep-seated grudge against other dwarven races, due to their exile from their midst.

Duergar have the ability to become invisible in the Forgotten Realms setting. In the Dragonlance setting, they are called daergar.

In the movie Van Helsing, duergar are small, loathsome creatures that serve Dracula.