Teun Koolhaas (7 January 1940 in Singapore – 3 October 2007 in Amsterdam) was a Dutch architect and urban planner.
When Southeast Asia was occupied by Japan, Teun and his mother were imprisoned in Tjideng camp in Batavia.
He then went on to study engineering at the Technical University of Delft, where he attended lectures by artists including Gerrit Rietveld and Cornelis van Eesteren.
In 1969 Koolhaas returned to the Netherlands, where he went to work for the architectural firm, Environmental Design SA.
As part of a team of architects, urban planners, sociologists, traffic planners and landscape architects, Koolhaas played an important role in creating the master plan for the new city of Almere in the south island of Flevoland, and was responsible for its urban design.