The 35-year-old paid 1.9 million for Killiechassie House, a 19th-century mansion on the banks of the River Tay, near Aberfeldy, Perthshire. The retreat is just a few miles from Castle Menzies, which has been likened to Hogwarts, the fictional school attended by the schoolboy wizard.
In the grounds is a sycamore tree said to have sheltered Bonnie Prince Charlie during the Jacobite Rising of 1745.
Ms Rowling’s wealth is estimated at 65 million, but her bank balance is growing by the hour thanks to the massive success of the film version of Harry Potter and The Philosopher’s Stone. It has already broken box office records and matched the record set by the last Star Wars movie as the fastest film to gross $100 million (65 million) in the United States.
The author, who lives with eight-year-old daughter Jessica and partner Dr Neil Murray in a 500,000-plus home in Merchiston, Edinburgh, bought Killiechassie House in June. However, the local residents were sworn to secrecy until the hype surrounding the 16 November release of the film died down.
Even the contractors working on renovations at her new home - which includes 162 acres of land and exclusive salmon fishing rights - are understood to have been asked to sign gagging clauses in their contracts.
Ms Rowling’s spokeswoman said the Perthshire home t is simply a retreat and the author has no plans to move there permanently.
Killiechassie House, built in 1865, has a principal bedroom suite and six further bedrooms.
It also has outer and inner halls, a drawing room, morning room, dining room, library, kitchen and various bedrooms and dressing rooms.
The house also has its own small loch, said to contain a murderous water sprite. William Jackson, of the Perth-based selling agents CKD Finlayson Hughes, confirmed the author had bought the house, which was once part of the Killiechassie Estate and is also close to the Aberfeldy Bridge, built by General Wade.
Mr Jackson said: "Killiechassie House is a most attractive family home. This area of Perthshire is most highly sought after with the most attractive countryside all around."
A spokeswoman for Ms Rowling also confirmed the purchase. The author also owns a 4.2 million house in Kensington, London.
Ms Rowling was named as the highest-paid woman in Britain - ahead of the Queen - in the last year by the Sunday Times pay list. Before the publication and runaway success of her first Harry Potter book, Ms Rowling was a single mother forced to survive on 70-a-week benefit.
She could barely afford to heat her tiny council flat and it was infested with mice. She had just enough funds to buy a weekly supply of nappies and regularly skipped meals in order to feed her child. She would spend her days walking around Edinburgh, pushing her daughter to help her fall asleep, before going to Nicolson’s Cafe for some warmth and to quietly scribble pages of her book about a boy wizard.
Ms Rowling’s share of the profits and merchandising from the film version of Harry Potter and the Philosopher’s Stone is expected to add another 40 million to her wealth.
The first four novels in the Harry Potter series all remain on the best-seller charts and the auction of the film rights for the Harry Potter series prompted a frantic bidding war between Stephen Spielberg and Disney.
Chris Columbus, director of the movie, began shooting the second Harry Potter film - The Chamber of Secrets - this week. It is hoped it will be released in November next year.
The fifth instalment in the seven-book series - entitled Harry Potter and the Order of the Phoenix is expected to be published next year.