Kristiansand is a city and municipality in Agder county, Norway. The city is the fifth-largest and the municipality is the sixth-largest in Norway, with a population of around 116,000 as of January 2020, following the incorporation of the municipalities of Søgne and Songdalen into the greater Kristiansand municipality. In addition to the city itself, Statistics Norway count four other densely populated areas in the municipality: Skålevik in Flekkerøy with a population of 3,526 in the Vågsbygd borough, Strai with a population of 1,636 in the Grim borough, Justvik with a population of 1,803 in the Lund borough, and Tveit with a population of 1,396 in the Oddernes borough. Kristiansand is divided into five boroughs; -Grim, which is located northwest in Kristiansand with a population of 15,000; Kvadraturen, which is the centre and downtown Kristiansand with a population of 5,200; Lund, the second largest borough; Søgne, with a population of around 12,000 and incorporated into the municipality of Kristiansand as of January 2020; Oddernes, a borough located in the west; and Vågsbygd, the largest borough with a population of 36,000, located in the southwest.

Søgne is a former municipality in the old Vest-Agder county, Norway. The municipality existed from 1838 until 2020 when it was merged with the municipalities of Songdalen and Kristiansand into the "new" Kristiansand municipality in what is now Agder county. It was located in the traditional district of Sørlandet, just outside of the city of Kristiansand. The administrative centre of the municipality was the hamlet of Tangvall. Hamlets and areas in Søgne include Ausviga, Eig, Høllen, Langenes, Lohne, Lunde, Ny-Hellesund, Trysnes, Vedderheia, Ålo, and Åros.