Australia’s controversial and outspoken iron ore queen Gina Rinehart has been knocked from her perch as the nation’s richest person – but you probably haven’t ever heard of the person who now holds the crown.

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

Ms Parry-Okeden, who lives in Scone – a centre of horse breeding in the Hunter Valley, NSW – has a US-based media fortune worth $US8.8 billion ($A12.5 billion).

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In a massive reversal of fortune, Ms Rinehart has fallen to second place with a net worth of $US8.5 billion ($A12.07 billion) after being worth an estimated $US17 billion in 2012.

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.

American-born Ms Parry-Okeden grew up in Hawaii and moved to Australia decades ago with her former husband. She is listed as Australian on this year’s rich list because she recently took up Australian citizenship.

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Blair Parry-Okeden’s net worth is valued at $12.5 billion.

Ms Parry-Okeden’s fortune emanates from the Atlanta-based Cox Enterprises media business. It has $US17 billion in revenues, is the third-largest cable TV company in the US as well as owning newspapers, radio, internet services, car auctions and online car sales.

Ms Parry-Okeden, 64, owns a quarter of the Cox group which she inherited when her mother died in 2007.

Cox Enterprises was started by James M. Cox in 1898 and is very much a family operation. Mr Cox’s daughter Anne Beau Cox Chambers, aged 95, is the majority owner, with a 50 per cent stake, and still sits on the company’s board of directors.

Grandson James Kennedy, who has 25 per cent, was CEO from 1988 to 2008 and now serves as chairman. His sister and James M. Cox’s granddaughter Ms Parry-Okeden has the remaining 25 per cent but has no role in the business.

She lives in rural Scone and is believed to be a keen rural property buyer as was her mother Barbara Cox Anthony.

Property baron Harry Triguboff ranks No.3 on this year’s list, with a net worth of $US6.9 billion ($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.

Reclusive rich-lister

In 2008, Ms Parry-Okeden donated $2 million to the Center on Aging at the University of Hawaii at Mānoa. The fund was named after her mother, Barbara Cox Anthony (pictured above), a longtime Honolulu resident, philanthropist and former director of Cox Enterprises.

Several years ago Ms Parry-Okeden bought a $575,000 cottage in Burradoo in the NSW Southern Highlands and has a “bolt hole” in the north shore Sydney suburb of Mosman – which apparently cost $750,000 in 1991.

Harry Triguboff, Australia’s third-richest person, is a residential property developer. Photo: AAP

From the early 1970s, Ms Parry-Okeden’s mother amassed an impressive portfolio of pastoral land including a quarter-horse stud at Collector, just north of Canberra.

In 1994 she doubled the size of her Wagga Wagga district holdings with a $4.6 million 4500-hectare purchase of Borambola Park. One of her last acquisitions was Oura station, bought in 1997 for $2.5 million, next to her Eringoarrah property in the Riverina.

There is a $2 million private bridge built across the Murrumbidgee that links the farms on both sides.

Ms Parry-Okeden is believed to have inherited her mother’s land holdings along with the stake in Cox Enterprises. Ms Parry-Okeden married a member of the rural establishment, Simon Parry-Okeden, but they have since divorced.

Like their mother, her two sons Andrew, 36, and Henry, 34, keep a low profile. They both reportedly have agricultural science degrees.

While they are some of the world’s richest people, the Cox family ethos is not about flashy lifestyles.

Ms Parry-Okeden’s 67-year-old brother James drives a Prius and says “none of the family has ever owned a Rolls Royce”.

Take a tour of Scone below:

-with AAP