Rinehart attended the Global Iron Ore & Steel Forecast Conference in Perth, where Roy Hill CEO Barry Fitzgerald was speaking.
She said the government was giving other countries an advantage by not addressing red tape.
"They need to cut back on over-regulation, licences and compliance costs which just push up the costs of mining in this country and give competitor nations with lower costs a better chance,” Rinehart said.
Roy Hill’s permitting process took years, with the project facing more than 4000 approvals, plus more for construction.
"When I ask members of government how many approvals and licences do they think Roy Hill has had to achieve, they say several hundred,” Rinehart said.
“They seem genuinely shocked when we tell them how many. Then, of course, the compliance burden needs to be met.”
Rinehart pointed out that Western Australia contributed near half of the country’s export revenue and 16% of gross domestic product, as well as taxes and royalties.
She said with the slump in commodity prices, the government needed to urgently address the “onerous” burdens.
"Australia can only accept where the iron price is and where it goes, and adapt to keep cost competitive as best it can, and that's where government has to do its bit.”
The $A10 billion Roy Hill project is more than 76% complete and remains on track for first ore on ship by September.