Niels de Vos will step down as chief executive of UK Athletics (UKA) at the end of September after almost 12 years in the role.
UKA's strategy and partnerships director Nigel Holl will take charge on an interim basis, while De Vos' successor is found.
Richard Bowker, UKA chairman, said: "The sport has grown and been hugely successful under Niels' leadership.
"He has been a fantastic servant to not only UKA, but athletics as a whole."
De Vos, 51, who is leaving to set up his own business, joined UKA in January 2007.
Under his leadership, Team GB won 13 medals, six of them gold, at both the London 2012 and Rio 2016 Olympics.
UK Athletics has also hosted the IAAF World Championships and World Para Athletics Championship, established the Anniversary Games in London and this year's inaugural Athletics World Cup.
Before his appointment at UKA De Vos was chief executive at Premiership rugby union side Sale Sharks.