He said: “As Chairman Les has been an essential part of the Association's move towards being a well governed organisation over the last five years.
“Without his guidance we would not have made such good progress nor would we have built such good relations with many of our external stakeholders.”
Les, a retired academic, became a director of the Irish FA in July 2007 and then replaced Allen McKinstry as Chairman of the Board in 2010
Under Irish FA rules a chairman can only serve for a maximum of five years.
Les Caul will remain on the Board as an Independent Director for another year.
He has been succeeded in the Chairman’s role by Gerry Mallon.