The Swedish Academy, which selects Nobel literature winners, called her a "master of the contemporary short story."
She's the first Canadian writer to receive the prestigious $1.2 million award since Saul Bellow, who won in 1976 and left for the U.S. as a boy.
Munro's writing has brought her numerous awards. She won a National Book Critics Circle prize for "Hateship, Friendship, Courtship, Loveship, Marriage," and is a three-time winner of the Governor General's prize, Canada's highest literary honor.
Often compared to Anton Chekhov, the 82-year-old writer has attained near-canonical status as a thorough, but forgiving, documenter of the human spirit.
Her published work often turns on the difference between Munro's growing up in Wingham, a conservative Canadian town west of Toronto, and her life after the social revolution of the 1960s.
In an interview with AP in 2003, she described the '60s as "wonderful."
It was "because, having been born in 1931, I was a little old, but not too old, and women like me after a couple of years were wearing miniskirts and prancing around," she said.
Last year's Nobel literature award went to Mo Yan of China.
The 2013 Nobel announcements continue Friday with the Nobel Peace Prize, followed by the economics prize on Monday.
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