Bertrand Lucien Bruno Cantat was born on March 5, 1964, in Pau, a city in the Pyrénées-Atlantiques region of France. He was the son of a navy officer, which meant his family moved around during his childhood. He spent a significant part of his early years in Le Havre, a port city in northwestern France. When he reached his adolescent years, his family relocated to Bordeaux.

In Bordeaux, Bertrand attended the lycée Saint-Genès. There, he met several classmates who would become important figures in his life. These friends included Denis Barthe, Serge Teyssot-Gay, and Frédéric Vidalenc. Together, they formed a band, which would later become known as Noir Désir. This band played a significant role in his life and career.

As he grew older, Cantat gained recognition in the French music scene. Over time, he would become well-known for his contributions as a musician and singer. His life before fame was marked by these early friendships and his growing interest in music. Alongside his musical journey, Bertrand eventually married Krisztina Rády, an art director of Hungarian descent, in 1997. Together, they had two children, Milo, born in 1998, and Alice, born in 2003.

In 2003, Bertrand Cantat was involved in a tragic incident that led to the death of French actress Marie Trintignant. On July 26, Cantat and Trintignant had an argument in their hotel room in Vilnius, Lithuania, related to a text message. Hours later, Trintignant was found in a coma, and she later died in the hospital from swelling of the brain.

During the investigation, it was discovered that Cantat had hit Trintignant multiple times in the head, which caused severe brain damage. In court, he admitted to slapping her several times, claiming he had acted out of jealousy. He stated that he did not realize the seriousness of her condition at the time.

Cantat was convicted of murder by a Lithuanian court and sentenced to eight years in prison. Following his conviction, both Trintignant's family and Cantat appealed the sentence. However, they later withdrew their appeals, allowing the original sentence to stand. Eventually, Cantat served four years of his sentence before being released on parole in October 2007.

After his release, public outcry ensued due to his past. On January 10, 2010, his former wife, Krisztina Rády, died by suicide while Cantat was at home. Investigations were conducted regarding Rády's death, but no charges were filed against Cantat.

In late 2010, he made a return to music with his band Noir Désir, but the group disbanded shortly after. Cantat continued his music career as a solo artist and later formed a duo named Détroit. His return to the public eye continued to spark debates, particularly regarding his past actions.