Kim Herforth Nielsen (born 1954) is a Danish architect, co-founder and principal of 3XN. He graduated from Aarhus School of Architecture in 1981 and has been a prominent figure in Danish and international architecture since then. Kim Herforth Nielsen has been at the forefront of a number of noteworthy projects, such as Ørestad College and Royal Arena in Copenhagen, the Danish Embassy in Berlin, International Olympic Committee's HQ in Lausanne and Sydney Fish Market.