Hidra is a former municipality that was located in the old Vest-Agder county in Norway. The 90-square-kilometre (35 sq mi) municipality existed from 1893 until its dissolution in 1965. It encompassed the islands and southern coastal part of the present-day municipality of Flekkefjord in what is now Agder county. The municipality included the islands of Hidra and Andabeløya as well as 56 other islands, plus the mainland coast from Abelsnes to the river Sira. The administrative centre was the village of Kirkehavn where Hidra Church is located.

Vest-Agder was one of 18 counties (fylker) in Norway up until 1 January 2020, when it was merged with Aust-Agder to form Agder county. In 2016, there were 182,701 inhabitants, around 3.5% of the total population of Norway. Its area was about 7,277 square kilometres (2,810 sq mi). The county administration was located in its largest city, Kristiansand.