This means Rowling – worth an estimated 800 million pounds– could walk down the red carpet to collect an Oscar for 'Harry Potter And The Deathly Hallows: Part 1', should the film win the Best Picture category.
Nominations for the 83rd Academy Awards will be announced in January, ahead of the ceremony in February.
The film earned more than 210 million pounds when it opened last weekend, and is likely to be the highest earner in the seven-film series.
"Jo had the option of taking a producer credit as early as the fourth film, but she chose not to until the final two films," the Daily Mail quoted David Heyman, who has produced all the films, as saying.
"Things were coming to an end and she wanted to put her stamp on it," he said.
However, the mother of three has always influenced production, insisting that the films be shot in Britain with an all-British cast.
Rowling, 45, who was once a struggling single mother, has sold more than 400 million books worldwide since the first Harry Potter was published in 1997.
Harry Potter is the most successful film franchise in history, selling 3.7 billion pounds worth of tickets.
