66-yr-old Robinson was awarded 30,000 pounds along with the Prize for her novel 'Home', and accepted it on Jun 3 at a ceremony at the Royal Festival Hall on the South Bank in London. Another contender for the prize had been Samantha Harvey, a 34-year-old from Bath, who had hoped she would take the women-only award for her first novel 'The Wilderness'.
'The Wilderness' is about a man's struggle to maintain his identity as Alzheimer's destroys his brain, and it had been a favourite among judges.
Last week bookmakers William Hill put it in second place with odds of 3/1, behind the favourite Ellen Feldman's Scottsboro, and he had given 'Home', about the relationships within an Iowa family, slightly longer odds of 7/2.
Fi Glover, the broadcaster and chair of judges, said the decision was an unusually easy one.
"Every single judge brought Home to the table as a potential winner. There certainly wasn't a night of the long knives," the Telegraph quoted her as saying.
There were two British contenders on the six-strong shortlist for the prize, which is awarded to "the best novel of the year written in English by a woman".
The second was Deirdre Madden from Northern Ireland, for her novel 'Molly Fox's Birthday'.
Glover has stressed that 'Home' was picked on the basis of "the book and not the pedigree of the author", adding that her writing had "a luminous quality to it".
She described 'Home' as a story about "families and redemption, or the reality of redemption and why sometimes you just may not be able to get there".
This is the 14th Orange Prize, which was set up "to celebrate and promote fiction written by women throughout the world".