Ole Kirk Christiansen (7 April 1891 – 11 March 1958) was the 10th son of an impoverished farmer family in Jutland in western Denmark. Born in Filskov, Denmark, he trained as a carpenter and started making wooden toys in 1932 to make a living after having lost his job during the depression. In 1942 a fire broke out at the factory forcing them to rebuild. Initially, he made miniature versions of the houses and furniture he worked on as a carpenter, but in 1947 moved onto using plastics. By 1949 he had produced over 200 plastic and wooden toys.

He came up with the name Lego from the Danish leg godt ("play well") and the company grew to become the Lego Group ("lego" coincidentally means "I put together" in Latin). On March 11 Christiansen died from a heart attack, his eldest son Godtfred Kirk Christiansen took over the company after his death and bought out his three brothers in 1960.

Ole Kirk Christiansen's grandson Kjeld Kirk Kristiansen is the current vice chairman of the board of LEGO. He was chief executive until 2004, when Jørgen Vig Knudstorp, a former McKinsey consultant, became the new head.