Lauritz Christiansen was a Danish long-distance runner who represented KIF Atletik. At the 1912 Stockholm Olympics Christiansen ran in the cross-country race where he finished in 14th place. He was the top-placed Dane in the event with his performance counting towards Denmark’s fifth place in the team classification. The following year Christiansen won the King’s Cup with victory in the national 15km cross-country race. In 1913 and 1914 he won the Fortunløbet, a race of just over 8 km, which was one of the best-known athletics events in Denmark. Christiansen won silver in the 5,000 metres at the national championships in 1911 and 1912, and a silver in the 1,500 metres in 1918.