Rinehart was 37th on the list, which was topped by German Chancellor Angela Merkel.
She was the only Australian on the 100-strong list, making her the most powerful woman in the country.
Forbes determined the rankings via four categories: money, media presence, spheres of influence and impact.
Earlier this year, Rinehart was named the 94th on Forbes’ annual billionaires list and the magazine pegged her current net worth at $US12.2 billion ($A15.7 billion).
Rinehart will realise long-held dream later this year when Hancock’s 70%-owned Roy Hill mine starts production.
The $A10 billion project is 81% complete and is on budget and schedule for first ore on ship in September.
It is expected to ramp up to 55 million tonnes per annum within 18 months.
