Steve Gunning, who for many years was chief executive of IAG Cargo, is to become chief financial officer of IAG.
He will replace Enrique Dupuy de Lôme, when he steps down in June.
Gunning has been British Airways CFO since January 2016 and acting director of IAG Global Business Services since December 2017.
He joined British Airways in 1998 becoming chief executive of British Airways World Cargo in 2007, going on to head IAG Cargo in 2011.
Willie Walsh, IAG chief executive, said: “I’d like to welcome Steve to his new role. His appointment serves as evidence of the strength and depth of the IAG leadership team.”