The Ebbsfleet Development Corporation announced that Robin Cooper is leaving his post as chief executive, and an interim CEO would join the organisation in January.
Cooper was appointed in April to drive forward delivery of the planned Ebbsleet garden city, which includes proposals to provide up to 15,000 homes.
Michael Cassidy, chairman of EDC, said: "Robin has been involved in the setting up of EDC through its early phase of development as the first Garden City for more than 100 years.
"We now move into a focused delivery phase where recruitment of experienced project managers will be a priority. The interim CEO will be well-placed to oversee this part of the programme. We wish to express our thanks for Robin's considerable efforts in helping us to date."
Cooper previously held the deputy chief executive and director of regeneration title at Medway Council.