"For being a legendary writer who has enriched Irish literature in inestimable ways and for nurturing French literature we award you the insignia of Commander of "L'Ordre des Arts et Lettres," said French culture minister Roselyne Bachelot-Narquin in a pre-recorded online message.
Bachelot-Narquin praised O'Brien for a "steadfast commitment in favour of liberty, both in your writing and in your life" and for "having inspired countless women by the force of your words".
O'Brien, 90, is the author of 18 novels.
"This award is huge for me," she said in a pre-recorded message from her home in London.
"I will wear this medal... as being talismanic for the rest of my life."
Born in 1930 into a strict Catholic farming family in west Ireland's County Clare O'Brien's father was an alcoholic and her mother saw writing as a sin.
"Writing was a very secret transaction because it was regarded as profane, both in our house and in my country, during my formative years," she explained in her acceptance speech.
O'Brien arrived on the literary scene in the 1960s, with a debut novel that was burned and banned in her native land.
"The Country Girls", about the sexual initiation of rebellious Catholic girls drawn from O'Brien's childhood experiences, is now a marker in modern Irish literature for its breaking of social and sexual taboos.
Her career spans decades with her most recent novel "Girl" published in 2019 -- depicting the trauma of Nigerian schoolgirls kidnapped by Boko Haram militants.
O'Brien has already been awarded the Irish PEN Lifetime Achievement Award and the PEN/Nabokov Award for work which "broke down social and sexual barriers for women in Ireland and beyond."
Her work is "like a piece of fine meshwork", wrote the late US author Philip Roth in the New York Times.
It is "a net of perfectly observed sensuous details that enables you to contain all the longing and pain and remorse that surge through the fiction," he said in 1984.
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© Agence France-Presse
