Thor actor Chris Hemsworth is fired up to help victims of the bush fires in Australia.

He is donating a million dollars.

"Like you, I want to support the fight against the bush fires. My family and I are contributing a million dollars. Hopefully you guys can chip in too," Hemsworth wrote on Instagram on Jan 7, from his home in Australia.

He provided links to "support the fire-fighters, organisations and charities" which are "working flat out to provide support and relief during this devastating and challenging time".

Elton John, who performed in Sydney on Jan 7, is also pledging a million dollars.

"There are people out there who have lost their lives trying to save homes.

"And there's the plight of the animals, a loss of their habitat that frankly is on a biblical scale and it's heartbreaking," he told the audience.

Both Hemsworth and John did not indicate the currency of their contributions.

With other A-listers like singers Kylie Minogue and Kacey Musgraves as well as actress Margot Robbie sending in their cheques, the Sydney Morning Herald estimated that A$140 million (S$130 million) has been raised, including more than A$45 million via a social media campaign by comedian Celeste Barber.