Rykiel, nicknamed the Queen of Knitwear, had been suffering from Parkinson’s disease for some time before her death on Thursday.
Nathalie Rykiel, managing and artistic director of the Sonia Rykiel fashion label, said: “My mother died at 05:00 this morning at her home in Paris from the effects of Parkinson’s.”
French President Francois Hollande praised her as “a pioneer”.
He said Rykiel, whose relaxed striped knitwear was seen as a shift away from more formal suits, had “offered women freedom of movement”.
Rykiel was born Sonia Flis in Paris in May 1930, to a Romanian father and Russian mother.
She started her career as a window dresser in 1948, with her first foray into design being when she knitted herself maternity dresses after marrying Sam Rykiel, the owner of a Paris boutique.
Rykiel made her breakthrough in 1962 with the so-called poor boy sweater, which had long sleeves and a fitted shape.
Elle magazine then featured teenage pop star Francois Hardy wearing a red and pink striped Rykiel sweater on its cover in December 1963.
Brigitte Bardot was later photographed in a Rykiel creation, with Audrey Hepburn among her other famous fans.
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