Gina Rinehart toppled as Australia's richest

In the past five years Ms Rinehart has topped Forbes Australia's rich list but this year she has been unseated by another woman. Photo / Getty

Gina Rinehart is no longer Australia's richest person.

In the past five years Ms Rinehart has topped Forbes Australia's rich list but this year she has been unseated by another woman, reclusive American heiress and longtime Australian resident Blair Parry-Okeden.

Parry-Okeden's net worth of $US8.8 ($A12.49) billion makes her the country's richest person while Rinehart has fallen to second place with a net worth of $US8.5 billion ($A12.07 billion).

Forbes says Parry-Okeden, who grew up in Hawaii and moved to her ex-husband's country of birth Australia decades ago, was recently confirmed to be an Australian citizen.

After her mother's 2007 death she inherited a quarter of American media conglomerate Cox Enterprises.

Forbes says Ms Rinehart's wealth has slipped $3.2 billion in the past year mainly due to falling iron ore prices and a legal ruling which impacted her shareholding in Hancock Prospecting.

Property baron Harry Triguboff ranks number three on this year's list, with a net worth of $US6.9 ($A9.79) billion.

Rising rents and increased demand for his Sydney apartments helped drive up Mr Triguboff's fortune by $1.3 billion, Forbes says.

Property sales of his apartment tower development company, Meriton, are expected to rise 70 per cent this year.

Top 10 richest Australians

1. Blair Parry-Okeden, $US8.8 billion
2. Gina Rinehart, $US8.5 billion
3. Harry Triguboff, $US6.9 billion
4. Frank Lowy, $US5 billion
5. Anthony Pratt, $US3.6 billion
6. James Packer, $US3.5 billion
7. John Gandel, $US3.2 billion
8. Lindsay Fox, $US2.8 billion
9. David Teoh, $US1.95 billion
10. David Hains, $US1.9 billion