Ms Greene, who had been poised to join the budget airline in September, will now take up the position of non-executive director with immediate effect.
She will “support the chief executive search process” after it was announced on Monday that Carolyn McCall is to join ITV in January.
In addition, Keith Hamill, who was supposed to retire from easyJet’s board as non-executive director on July 31, will stay on, also to help out with the recruitment process.
Ms McCall has headed up the low-cost airline since 2010, but she leaves the low-cost carrier at a difficult time for the sector in Britain, with Brexit storm clouds gathering over the travel industry.
The pound’s collapse has meant less people travelling overseas and, more starkly, British airlines are at risk of being grounded unless bumbling Tory ministers strike an aviation deal with the EU before March 2019.