A judge handed Benzema a one-year suspended jail term and ordered him to pay a €75,000 fine.
Benzema was one of five people put on trial last month over an attempt to extort Frenchman Mathieu Valbuena.
The scandal has stunned the football community in France and both players lost their national team places.
The case dates back to June 2015, when the two footballers were at a French training camp.
At the camp, Benzema put pressure on Valbuena to pay off the blackmailers, whom he had conspired with to act as an intermediary, prosecutors said.
The player has since returned to the France team and is expected to start for Real Madrid on Wednesday night when they play FC Sheriff Tiraspol in the Champions League.
Benzema was not present in court in Versailles for the verdict, nor was Valbuena who plays for Greek club Olympiakos.
Four of Benzema's co-defendants in the trial were also found guilty on Wednesday.
Benzema's lawyers said they would appeal his conviction. "The reaction is ultimately an angry one to this judgment which is perfectly contradictory," his lawyer, Sylvain Cormier, told reporters outside court.
But when delivering the verdict, the judge said Benzema was "personally involved" in the scheme to extort money.