The actor was also widely recognised in France for his long-running television work, particularly his role in the soap opera Demain Nous Appartient, known internationally as Tomorrow Belongs To Us.
His daughters said in a statement: “It is with deep emotion that we announce the passing of Pierre Deny, which occurred this Monday following a sudden and severe case of ALS.”
ALS is a degenerative nervous system disease affecting nerve cells in the brain and spinal cord, gradually leading to loss of muscle control and paralysis.
There is currently no cure for the condition.
Tributes to Deny quickly emerged across the French entertainment industry following news of his death.
Bulgarian-French singer and actress Sylvie Vartan paid tribute on Instagram following their work together on stage in a play by playwright Isabelle Mergault.
“It is with great sadness that I learned of the passing of Pierre Deny.I shared many wonderful moments with him on stage in Isabelle Mergault’s play.”
Vartan added: “He was a generous actor and a sensitive and funny man. In these painful moments, my thoughts are with his family and loved ones.”
Actor Luce Mouchel, his co-star on Demain Nous Appartient, also paid tribute.
“Pierre, seven years of filming together, taking the train together, having lunch at the canteen together.”
She added: “A short decade of shared life that should not have ended so quickly and so brutally”.
Mouchel also praised his daughters for what she described as their “exceptional courage”.
Deny’s death comes amid growing awareness around ALS following the recent death of Grey’s Anatomy actor Eric Dane, who died in February aged 53 after publicly revealing his diagnosis in 2025.
Dane, best known for playing Dr Mark Sloan – nicknamed “McSteamy” – in the long-running medical drama, had spoken openly about the devastating impact of the illness in interviews before his death.
Dane’s wife, Rebecca Gayheart, spoke publicly about the family’s struggles following his diagnosis.
She told People: “I mean, it’s heartbreaking”.
“My girls are really suffering, and we’re just trying to get through it. It’s a tough time.”