The Acacus Mountains or Tadrart Akakus (Arabic: تدرارت أكاكوس / ALA-LC: Tadrārt Akākūs) form a mountain range in the desert of the Ghat District in western Libya, part of the Sahara. They are situated east of the city of Ghat, Libya, and stretch north from the border with Algeria, about 100 kilometres (62 mi). The area has a particularly rich array of prehistoric rock art.

The area is known for its rock art and was inscribed as a UNESCO World Heritage Site in 1985 because of the importance of these paintings and carvings. The paintings date from 12,000 BCE to 100 CE and reflect cultural and natural changes in the area.

There are paintings and carvings of animals such as giraffes, elephants, ostriches, and camels, but also of humans and horses. People are depicted in various daily life situations, for example, while making music and dancing.