Steven Harding is leaving after almost five years to join public affairs and comms firm Pall Mall Consult as a director.
Before joining the Royal Institute of British Architects, Harding worked at the former British Tourist Authority. He starts the new role later this month.
The Royal Institute of British Architects has selected Harding's successor, appointing NHS Confederation campaigns manager Anna Scott-Marshall as head of public affairs. She leaves the NHS Confederation after four years, having joined from Diabetes UK.
The NHS Confederation is planning to replace Scott-Marshall, who reports to deputy director of comms Sarah Jones.