Gina Rinehart is the highest ranking Australian on the Forbes rich list, coming in at number 29.
The West Australian mining magnate is the only Australian to make the top 100, with Forbes estimating her wealth at $US18 billion ($17.12 billion).
A total of 18 Australian citizens made the list of the world's richest people.
She's beaten News Corp boss mogul Rupert Murdoch who came in at number 106. Forbes lists the 80-year-old Murdoch as an American because he has US citizenship.
Fellow miner Andrew "Twiggy" Forrest, came in at number 173 with $US5.8 billion while James Packer is further down the list at 223, with his gaming empire estimated to be worth $US4.7 billion.
Mexico telecoms tsar Carlos Slim topped the Forbes annual world's richest list, sporting a $US69 billion fortune that while down from last year still outpaced the runner-up, Microsoft founder Bill Gates.
Forbes said 1226 tycoons made it onto its global list of billionaires this year, but Slim held onto the top spot for the third straight year, with $7 billion more than Gates.
In the third spot was US investment guru Warren Buffet, worth $44 billion; followed by France's luxury king Bernard Arnault, $41 billion; and a newcomer to the top five Spain's Amancio Ortega, whose net worth surged by $6.5 billion despite his country's financial straits to hit $37.5 billion.
"In a year of churn and burn, 128 billionaires are new to the list... while 117 dropped off," said Forbes.
"A record 1226 billionaires [up from 1210 in 2011] made the list, with an average net worth of $3.7 billion," the same as last year.