Arnault, a major cultural figure in Sweden, faced two counts of rape of a woman seven years ago, in a scandal that rocked the prestigious Nobel Prize academy with seven members either being forced to leave or quitting.
The man at the centre of a sex-abuse and financial crimes scandal that is tarnishing the academy that awards the Nobel Prize in Literature was convicted on Monday and sentenced to two years in prison for a rape in 2011.
Jean-Claude Arnault, a major cultural figure in Sweden, had faced two counts of rape of a woman seven years ago.
Stockholm District Court said that the ruling was unanimous.
"The defendant is found guilty of rape committed during the night between the 5th and 6th of October 2011 and has been sentenced to imprisonment for two years. The injured party has been awarded compensation for damages," the Stockholm district court announced in its verdict.
Judge Gudrun Antemar said the role of the court was to decide whether the prosecutor had proven the charges beyond a reasonable doubt.
"The court's conclusion is that the evidence is enough to find the defendant guilty of one of the events," she said, adding the evidence "has mainly consisted of statements made during the trial by the injured party and several witnesses."
The scandal erupted in November 2017, one month after rape and sexual abuse accusations surfaced against Hollywood mogul Harvey Weinstein.
At the time, Swedish daily Dagens Nyheter published the testimonies of 18 women claiming to have been raped, sexually assaulted or harassed by Arnault, who had close ties to the Academy.
The Frenchman also ran the Forum club, a meeting place for the cultural elite and popular among aspiring young authors hoping to make contact with publishers and writers.
Impact on Nobel academy
In Sweden, rape is punishable by a minimum of two years and a maximum of six years in prison.
Prosecutor Christina Voigt had demanded three years in prison for Arnault, who is married to a Swedish Academy member.
Arnault had denied the charges, which have rocked the prestigious academy, forcing the Swedish Academy to cancel this year's literature prize, which would have been announced this month, and prompted some of its 18 members to quit.