Keith shared the same message on his own Instagram account, ensuring the message reached his 2.2 million followers, along with Nicole's 6 million.
While they are primarily based in the US these days, the couple do own a home in Australia – which, according to their rep, is also currently under threat from the catastrophic fires.
Speaking to E! News, the rep explained: "Their house is not on fire. It is under threat, so keeping a close eye on it."
The celebrity duo had been in Australia for the Christmas holidays, but were back in the United States by New Year, when Nic watched Keith perform in Nashville to ring in 2020.
Nicole and Keith aren't the first celebs to open their hearts – and their wallets – to help the people and animals who have been left displaced, injured and devastated by the horrifying events Down Under. Singer Pink also made an incredible pledge toward Australia's frontline firefighters as the nation's bushfire crisis continues.
Taking to Twitter, the artist expressed her distress at the country's emergency.
"I am totally devastated watching what is happening in Australia right now with the horrific bushfires," she said.
"I am pledging a donation of $500,000 directly to the local fire services that are battling so hard on the frontlines.
"My heart goes out to our friends and family in Oz."
"Want to join me in supporting a good cause?" she wrote on the campaign's Facebook page.
"I'm raising money for The Trustee for NSW Rural Fire Service & Brigades Donations Fund and your contribution will make an impact, whether you donate a lot or a little.
"Anything helps. Thank you for your support."
She also took to her Instagram stories to reassure her followers that, while the donations began for the NSW RFS, she intends to make sure the funds a spread around the states, and shared amongst everyone who needs them.