Murzuk, Murzuq, Murzug or Merzug is an oasis town and the capital of the Murzuq District in the Fezzan region of southwest Libya. It lies on the northern edge of the Murzuq Desert, an extremely arid region of ergs or great sand dunes which is part of the greater Sahara Desert.

In ecology, an oasis is a fertile area of a desert or semi-desert environment that sustains plant life and provides habitat for animals. Surface water and land may be present, or water may only be accessible from wells or underground channels created by humans. In geography, an oasis may be a current or past rest stop on a transportation route, or less-than-verdant location that nonetheless provides access to underground water through deep wells created and maintained by humans.