Kjeld Kirk Kristiansen (; born 27 December 1947) is a Danish businessman who was the president and chief executive officer of the Lego Group from 1979 to 2004. According to Forbes, Kristiansen has an estimated net worth of billion as of December 2025. He is the grandson of Lego founder Ole Kirk Christiansen.
Kristiansen was born 27 December 1947 in Billund, Denmark. His father, Godtfred Kirk Christiansen, worked with his grandfather, Ole Kirk Christiansen, in the family business: Lego. As a child, he often inspired and tested new model concepts and their building instructions. He also appeared on many of the company's packages and marketing materials.
Kristiansen graduated with a bachelor's degree from Aarhus University. In 1972, he received an MBA from IMD Business School in Switzerland.
In 1979, Kristiansen became president and CEO of The Lego Group. He introduced themes, minifigures, LEGO.com, Lego Mindstorms and licensed properties. In 2004, he stepped down as president and CEO to focus on his role as owner of the Lego Group and vice-chairman of the board, while maintaining his role as chairman of the board of KIRKBI A/S, Lego Holding A/S and the Lego Foundation. Lego is privately held and is controlled by the Kristiansen family and their foundations.
Kristiansen and his wife, Camilla, live in Denmark and have three children: Thomas Kirk Kristiansen, Sofie Kirk Kristiansen, and Agnete Kirk Thinggaard, a Danish Olympic dressage rider.
In 1995, Kristiansen bought Strathconon Estate, in the highlands of Scotland, covering . He later bought the neighbouring Scardroy and Ledgowan estates.
He has received many awards in his professional career.