Alexievich, 67, used the skills of a journalist to create literature chronicling the great tragedies of the Soviet Union and its collapse: The Second World War, the Soviet war in Afghanistan, the Chernobyl nuclear disaster, and suicides that followed the death of Communism.
Her first novel, The Unwomanly Face Of The War, published in 1985 and based on the stories of women who had fought against the Nazis, sold more than 2m copies.
Her books have been published in 19 countries. She has also written three plays and the screenplays for 21 documentary films.
The Swedish Academy hailed Alexievich “for her polyphonic writings, a monument to suffering and courage in our time”.
The Nobel Peace Prize will be announced today and the economics award will be revealed on Monday.
The academy’s permanent secretary, Sara Danius, praised Alexievich as a great and innovative writer.
“She transcends the format of journalism and has developed a new literary genre that bears her trademark,” said Danius.
The daughter of two village schoolteachers, Alexievich studied journalism in Belarus, a former Soviet state.
She lives in the, capital Minsk, and, like many intellectuals, supports the political opponents of authoritarian president Alexander Lukashenko, who is up for re-election on Sunday.
Speaking by phone to Swedish public service television SVT, Alexievich said on winning: “On the one hand it’s such a fantastic feeling, but it’s also a bit disturbing.” She said she was at home “doing chores, I was doing the ironing” when the academy called her.
She said she is going to use the prize money, 8m Swedish krona (€860,000) to buy her freedom to write.