Halse og Harkmark is a former municipality in the old Vest-Agder county, Norway. The 105-square-kilometre (41 sq mi) municipality existed from 1838 until its dissolution in 1964. The administrative centre of the municipality was the village of Halse, which at that time was a suburb of the town of Mandal. It was located in the southern part of the municipality of Mandal. The municipality of Halse og Harkmark encompassed the rural areas that surrounded the town of Mandal, including many islands such as Hille, Skjernøy, and Pysen. It is now located within Lindesnes Municipality in what is now Agder county.

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.