The controversial BA boss has been replaced immediately as chief executive by Sean Doyle, currently the chairman and CEO of Aer Lingus.
Both airlines are part of the IAG consortium. Mr Cruz will keep his role as chairman temporarily, but Mr Doyle will take over as chairman “after a transition period,” according to IAG.
Mr Cruz became chairman and chief executive of British Airways in April 2016. He arrived after serving as chief executive of the low-cost airline, Vueling.
During his tenure, he oversaw significant changes at BA – including the introduction of “buy on board” to replace complimentary catering in economy class on short-haul flights.
He also faced industrial action by cabin crew and pilots – with a strike by the flight crew dampening celebrations of the airline’s centenary.
Mr Cruz also had to deal with a catastrophic IT failure at the airline in 2017, and a data breach in 2018.
British Airways has been hit extremely hard by the coronavirus pandemic. Mr Cruz announced up to 12,000 job losses from a workforce of 42,000.
The outgoing BA chief executive was widely seen as the personal choice of Willie Walsh, who stepped down as CEO of IAG last month.
Luis Gallego, chief executive of IAG, said: “I want to thank Alex for all that he has done at British Airways. He worked tirelessly to modernise the airline in the years leading up to the celebration of its 100th anniversary.
“Since then, he has led the airline through a particularly demanding period and has secured restructuring agreements with the vast majority of employees.”
Sean Doyle joined British Airways in 1998 and became director of network, fleet and alliances before moving to Aer Lingus as CEO in January 2019.
He is being replaced at Aer Lingus on an interim basis by Donal Moriarty, currently the Irish airline’s chief corporate affairs officer.
Brian Strutton, general secretary of British Airline Pilots’ Association (Balpa), said: “Mr Cruz has been in the departure lounge for some time so this is no surprise.
“He was given a remit to cut costs and found it impossible to do that without alienating BA passengers and employees alike.
“I hope this heralds a new dawn which sees BA behaving like the proud flag carrier airline it should be. Balpa looks forward to working constructively with the new CEO, Sean Doyle.”