Lars Christensen was born in Sandar. Born into a wealthy family, Christensen inherited his whaling fleet from his father, Christen Christensen. He started his career as a ship owner in 1906. He ventured into the whaling industry in 1909, and directed several companies, including Framnæs Mekaniske Værksted, AS Thor Dahl, AS Odd, AS Ørnen, AS Thorsholm and Bryde og Dahls Hvalfangstselskap.
Endurance, the ship that became famous after Sir Ernest Shackleton's failed Imperial Trans-Antarctic Expedition of 1914, was originally built for Christensen, who intended to use her for Arctic cruises for tourists to hunt polar bears. When this did not happen, Christensen sold the ship to Shackleton.
Christensen had a deep interest in Antarctica and its animal life. He was particularly interested in making geographical discoveries, and gave his captains wide latitude to do so. He financed several expeditions specifically devoted to the exploration of the Antarctic continent and its waters, and participated in some of these himself, even bringing his wife Ingrid with him in the 1936–1937 expedition. He was among the first to use aerial surveying with seaplanes to map the coast of East Antarctica, which he completed from the Weddell Sea to the Shackleton Ice Shelf, concentrating on Bouvetøya and the region from Enderby Land to Coats Land. From the seaplane brought on the 1936–1937 expedition, members took 2,200 oblique aerial photographs, covering 6,250 square miles (16,200 km2). Mrs Christensen became the first woman to fly over the continent.
On 1 December 1927, as the leader of one of his financed expeditions, Christensen landed on and claimed the Bouvet Island for Norway; it had previously been claimed by Great Britain, but the British soon abandoned their claim and recognised the island as Norwegian.
On the expeditions he financed between 1927 and 1937, Christensen's men discovered and surveyed substantial new land on the Dronning Maud Land and MacRobertson Land coasts. Places in Antarctica named after Christensen include the Lars Christensen Peak, the Lars Christensen Coast as well as Lars Christensen Land, also known as MacRobertson Land, where the (now closed) Russian Soyuz station operated. In addition, Ingrid Christensen Land was named after Christensen's wife, one of the first women to visit Antarctica.
Together with Otto Sverdrup and Oscar Wisting, Christensen initiated an expedition to recover another famous ship, the Fram. In 1935 the Fram was installed in the museum where it now stands; the Fram Museum in Oslo.
Christensen was also a patron of the controversial Austrian psychoanalyst Wilhelm Reich during his exile in Norway between 1934 and 1939. In 1935 he gave NOK 20,000 to Reich to be used on scientific equipment as Reich was establishing his International Institute for Sex Economy.
Christensen was a fellow of the Royal Norwegian Society of Sciences and Letters and received its Gunnerus Medal, and an honorary fellow of the Norwegian Academy of Science and Letters. He was decorated as a Commander of the Order of St. Olav and the Order of Vasa, and a Knight of the Order of Dannebrog.
Sandefjord Whaling Museum was donated to Sandefjord in 1917. This was one of the first dedicated museum buildings in Norway. In his travels, Christensen collected a considerable volume of literature, including much on the subject of whaling; his interests included research as well as merely supporting the industry. This material was donated to the library of Sandefjord Museum in the 1920s and 1930s. Christensen also provided funds for the further expansion of the Whaling Museum's library, which was overseen by shipping broker, author and consultant Bjarne Aagaard, whose extensive book collection also formed a major addition to the library.
- "Lars Christensen". Store norske leksikon. Kunnskapsforlaget.
- Hoffstad, Einar, ed. (1935). "Christensen, Lars". Merkantilt biografisk leksikon (in Norwegian) (1st ed.). Oslo: Yrkesforlaget. p. 138. Retrieved 29 December 2011.
- Søbye, Espen (1995). Rolf Stenersen. En biografi (in Norwegian). Oslo, Norway: Forlaget Oktober. p. 195. ISBN 82-7094-681-8.