Speaking on ITV's Peston, Michael O'Leary said it had "never been worse" for the airline industry.
He said the UK government's scheme of taking places off the quarantine list only to add them on a few weeks later - like they did with Portugal - means no one will have the confidence to fly.
He praised the EU's travel plan which will come that allows European travellers to move freely between nations, with only certain regions being unavailable.
The regions will cover large cities or entire tourist areas, but not encompass whole nations.
He said no one at the moment could make travel plans "with any certainty," but the EU plan would change that.
Mr O'Leary said Italy and Germany had been able to allow unrestricted travel while also keeping cases low, something the UK hadn't done.
The travel industry has been one of the worst hit during the pandemic, with many nations banning their citizens from going to large parts of the world, or being told to self-isolate when they return.
He said: "We operated about 50 per cent of our schedule through August. September, we expect to operate only 40 per cent of our schedule into October.
"And at the moment November and December look like they're booking at around ten per cent of our normal volumes.
"And that's a number that's repeated across most of the European and the UK airline industry. We have never seen such awful forward bookings."
ITV News Political Editor Robert Peston asked Mr O'Leary why he had taken a £500,000 bonus when the air industry was in such dire straights.
Mr O'Leary said he had taken a large pay cut already and his bonus was half what it was last year.
He also said the bonus was awarded for the financial year up to March so it did not include the company's performance the height of the pandemic.