Government data from 2016 to 2021 was analysed for the report, commissioned by advocacy groups Greenpeace and RSPCA Queensland.
"We came up with a pretty startling figure, about 100 million ... most of that is reptiles," report author Martin Taylor from the University of Queensland said.
"We're looking at about 1200 koalas a year is my estimate, losing their habitat and ultimately dying as a result of clearing," Dr Taylor told AAP.
About 2.4 million hectares of forest were cleared across two states from 2016 to 2021. (HANDOUT/GREENPEACE AUSTRALIA PACIFIC)
The academic said deforestation was the result of beef production, although the cattle industry has denied the scale of the problem.
Cattle Australia chief, Chris Parker, who represents grass-fed beef cattle producers, last week took aim "at the the growing list of environmental non-governmental organisations" for cherry-picking science to attack Australia's beef industry.
"Livestock pasture development specifically is the largest driver of land clearing in Queensland and in NSW ... taken together we're looking at 90 per cent," Dr Taylor, a former conservation scientist with WWF Australia, said.
The report found the remaining 10 per cent of land clearing in the two states could be attributed to cropping and plantations, urban development and forest logging.
Cattle Australia and the National Farmers' Federation has been contacted for comment.
The new report showed 2.4 million hectares of forest and woodland habitats, which was either mature or advanced regrowth, were bulldozed or cleared across the two states from 2016 to 2021.
That is about twice the size of greater Sydney.
Agricultural land clearing had almost halved in Queensland between 2018 and 2021, from 609,544 hectares to 311,809 hectares, while land clearing in NSW increased to 85,954 hectares during the same period.
The report found existing laws continue to be "inadequate to prevent the ongoing, unmitigated suffering and killing of native wildlife that results from bushland destruction".
"Little has improved for wild animals since our last report on this crisis in 2017 ... laws and policies in both states have not greatly changed and still allow very large areas of bushland habitat for wildlife to be destroyed every year," the report said.
Regulation of land clearing is primarily the responsibility of state and territory governments.
"We're calling for stronger nature laws that will halt nature destruction and end the extinction crisis in Australia," Greenpeace's Gemma Plesman said.
Federal environment minister Tanya Plibersek said the Albanese Government is doing more than ever to protect Australia's iconic native plants and animals.
"We're reforming Australia's national environment laws because we know they don't adequately protect our environment and they don't work for business," she said in a statement.
"Environment Protection Australia will be a tough cop on the beat with strong powers and penalties – including for cracking down on illegal land clearing."
The NSW and Queensland governments have been contacted for comment.
The report also examined RSPCA data on wildlife hospital admissions throughout Queensland, and found urban development is largely to blame for animals being injured.
On average, 24,000 native animals including more than 500 koalas were recorded by RSPCA Queensland being rescued or admitted into its care every year.
"They're not suffering because the bulldozer has pushed over their tree, they're suffering because they're left with these little patches of habitats surrounded by busy roads and dogs," Dr Taylor said.
About two-thirds of all animals taken to hospital died after admission.
