The section to Larvik Station was opened on 13 October 1881 and the remainder, including an extension to Skien Station, opened on 23 November 1882. The line was originally variously known as the Drammen–Skien Line (), the County Line () and the Jarlsberg Line (), until it became known as the Vestfold Line. Horten was served via the now closed Horten Line from Skoppum Station. Three other branches were later built: the Brevik Line (1895), the Tønsberg–Eidsfoss Line (1901) and the Holmestrand–Vittingfoss Line (1902). The latter two were private and closed in 1938. The Vestfold Line received gauge conversion from the original narrow gauge in 1949, as the last mainline railway in Norway. It was electrified in 1957.