The author criticised the Loiseau des Ducs in July 2013, saying it was "very overrated, all for show and with very little on the plate. The most plentiful plate was the one carrying the bill".
But the comment was published before the restaurant opened to the public.
The court ruled that it could not have been based on a real experience.
It said the review aimed to deter future customers, and ordered the author to pay €2,500 in damages and €5,000 towards the cost of the investigation.
The reviewer, who was not named in French media reports, posted the comment on France's Pages Jaunes website under the pseudonym The Clarifier five days before the restaurant, run by the Bernard Loiseau group, opened.
Group director Ahlame Buisard said the company was not against real customers expressing positive or negative opinions, but that the case against the fake review was a point of principle.
Bernard Loiseau, one of France's most celebrated chefs, committed suicide in 2003 after his flagship restaurant was downgraded in a top restaurant guide.
Loiseau des Ducs received its one Michelin star in February 2014.
A court in France has fined an internet user €2,500 (£1,800; $2,800) for posting a false and malicious review of a Michelin-starred restaurant in Dijon.