Audnedal is a municipality in the county of Vest-Agder, Norway. The new municipality of Audnedal was created on 1 January 1964 after the merger of Grindheim and Konsmo.

The old municipality (see Undal) had quite different borders: It was established as a municipality on 1 January 1838 (see formannskapsdistrikt) but in 1845 it was divided into Nord-Audnedal (divided in Konsmo and Vigmostad in 1911) and Sør-Audnedal (Spangereid separated in 1899).

It is an inland municipality, and Åseral municipality borders it to the north, Hægebostad to the west, Lyngdal and Lindesnes to the south, and Marnardal to the east. In the north-east it borders Evje og Hornnes in the county of Aust-Agder.

The Old Norse form of the name was Auðnudalr. The first element is the genitive case of the river name Auðna (now Audnedalselva) and the last element is dalr which means "valley" or "dale". The river name is derived from the Norse word auðn which means "destruction" (because of flooding).

The coat-of-arms is from modern times. They were granted on 30 August 1991. It shows a blade of a circular saw to represent the timber and forestry industries in the municipality.