Constantinos A. Doxiadis, often cited as C. A. Doxiadis, was a Greek architect and urban planner. During the 1960s, he was the lead architect and planner of Islamabad, which was to serve as the new capital city of Pakistan. He was later known as the father of ekistics, which concerns the multi-aspect science of human settlements.

Plan for Skopje 1963 was the urban and architectural plan put forward to rebuild the city of Skopje following the 1963 Skopje earthquake. The plan was organised between 1963 and 1966 by the government of Yugoslavia and the United Nations. The rebuilding of the city attracted large international attention, this led to the involvement of a large number of high-profile architects. The UN invited Kenzo Tange and his team to participate in an international competition for the urban design of the city centre in 1965; as one of several Yugoslav and international architecture teams. Architects that participated in the plan include Greek architect Constantinos Doxiadis and Polish architect Adolf Ciborowski. Dutch architects Van den Broek and Jaap Bakema. Luigi Piccinato (Italy) and Maurice Rotival (USA). Yugoslav participants included Aleksandar Dordevik, Slavko Brezoski, Edvard Ravnikar, Radovan Miščević and Fedor Wenzler.