The court in Versailles, west of Paris, said Franco-Algerian Mehdi Nemmouche, 29, who was detained several days after the attack, should be handed over to Belgian authorities for "killings with a terrorist connotation."
The decision was in line with a European warrant issued for Nemmouche's arrest.
The suspect had initially said he was not opposed to his transfer to Belgium as long as he had assurances he would not be sent on to a third country, but then decided to contest the extradition.
He was arrested on May 30 in the southern city of Marseille in a bus coming from Brussels during a random check by customs officials.
A revolver and Kalashnikov rifle were found in his luggage - similar weapons to those used in the shooting - as was a portable camera.
A Jewish couple was killed in the shooting, as was a French woman and Belgian man.