Lellouche was born in Savigny-sur-Orge, France, to a father of Algerian-Jewish descent, and to a mother of Irish Catholic background.

[6] Since 2015, Lellouche has been in a relationship with former model and jewelry designer Alizée Guinochet, with whom he had a son, born in November 2022.

[7] In January 2017, following the backlash over director Roman Polanski being appointed as the president of the 2017 César Awards while being convicted of sexual abuse of a 13-year-old girl and being a fugitive from justice since 1978, Lellouche expressed his support for the director in an interview with Le Parisien, saying; "In France, we make controversies of everything.

But we welcomed him, we gave him awards, we praise him since he is a big director and he is part of the history of cinema.

"[8] Polanski later dropped out of presiding over the Césars after the backlash, which included a 61,000-signature petition and calls to boycott the ceremony.