Dublin Zoo has raised more than €1million in donations since it launched a fundraising campaign earlier on Wednesday.
The cost of feeding and looking after animals can run to around half €500,000 a month, but it is closed to the public due to the coronavirus restrictions.
It has warned it will have to close its gates for good if it cannot find a way to plug an almost €10million deficit caused by Covid-19.
The Zoo tweeted: "Orang' of applause to you all!
"Never in our wildest dreams did we think we'd get here - let alone this soon!
"We have reached a mind blowing €1,000,000 - and it's all thanks to you!"
Meanwhile, the Government has confirmed it will step in to keep the zoo afloat.
Taoiseach Micheal Martin said: "The Government does not want Dublin Zoo to close and we will do everything we possibly can to ensure Dublin Zoo stays open.
"In my view given the extraordinary circumstances of a global pandemic, a once in 100-year event, Government has to intervene here.
"Government has to work with Dublin Zoo to ensure that it's available for generations to come."
While the zoo does not ordinarily receive capital funding, an exception is being made in the context of the global pandemic.
Heritage Minister Malcolm Noonan said he is considering short-term options to give the required funding to both Dublin Zoo and Fota Wildlife Park.
He tweeted: "The outflow of public goodwill in terms of donations is testament to the high regard that these places have in our public consciousness. The loss of Dublin or Fota is unthinkable."
Dublin Zoo is one of the most popular tourism attractions in the country. It has lost millions in admissions fees in a matter of months after it was forced to close during the pandemic.
Launching the fundraising campaign on Wednesday, zoo director Christoph Schwitzer said the facility faces an estimated loss of €8.2million in revenue so far this year.
He told RTE's Morning Ireland: "You can't furlough an elephant, you can't switch off a zoo at night when you go home.
"Our animals need and deserve 24/7 care and we provide the highest standards of animal care and welfare possible.
"Animal care alone costs us half a million a month, and these are very high fixed costs, and with no income from visitation, of course, we have difficulty meeting them."
As part of the fundraising initiative, Dublin Zoo has rolled out new adoption packages for its animals.
