is a municipality in Agder county, Norway. It is located in the traditional district of Lister. The administrative centre of the municipality is the town of Alleen. Some of the main villages in Lyngdal include Austad, Byremo, Fleseland, Hæåk, Konsmo, Korshamn, Kvås, Skomrak, Svenevik, and Vivlemo.

Austad is a former municipality of the former Vest-Agder county, Norway. The 44-square-kilometre (17 sq mi) municipality existed from 1909 until its dissolution in 1963. The municipality encompassed the area surrounding the Rosfjorden in the southern, coastal part of the present-day municipality of Lyngdal. The administrative centre of the municipality was the village of Austad where Austad Church is located.