Born in Aix-les-Bains, Savoie, in 1952, he was elected by the general assembly of the Central Consistory chief rabbi of France on 22 June 2008, for a seven-year mandate starting from 1 January 2009.

[2] However, he resigned as chief rabbi in April 2013 before his term had ended, amid revelations of plagiarism and deception about his academic credentials.

In October 2012, he took a clear position against gay marriage in a plagiarized essay entitled "Mariage homosexuel, homoparentalité et adoption : ce que l’on oublie souvent de dire"[5] (approximately equivalent to "Gay marriage, gay parenting and adoption: What we frequently forget to mention" in English) « The problem in the proposed legislation, the harm it would cause to our entire society for the sole benefit of a tiny minority, once they have irreversibly blurred three things: This essay found a strong echo in Roman Catholic circles, culminating in Pope Benedict XVI quoting him at length in his annual address[6][7] to the Roman Curia, 21 December 2012 "The Chief Rabbi of France, Gilles Bernheim, has shown in a very detailed and profoundly moving study that the attack we are currently experiencing on the true structure of the family, made up of father, mother, and child, goes much deeper."

[9] The affair started in early March when the Strass de la Philosophie blog revealed that a passage on hasidic exegesis from Bernheim’s work was almost identical to an interview of the philosopher Jean-Francois Lyotard that appears in the 1996 book "Questioning Judaism" by Elisabeth Weber.

Le Figaro reported that "there was heavy pressure" on the part of unnamed officials from the Jewish community for Bernheim to resign.