Search and rescue teams were called to a small vessel near the beaches of north town Berck-sur-Mer, where at least one person was overboard, French maritime authorities said.
Twenty-five individuals who remained on board were towed to the coast, while five were recovered from a sandbank by firefighters.
A Sudanese national, in his twenties, was unconscious and was declared dead after being taken back to shore.
An investigation has been launched into the incident by the Boulogne-sur-Mer prosecutor.
Steve Crawshaw, director of policy and advocacy at Freedom from Torture, said that in light of the tragedy, he was “deeply disturbed” by reports that home secretary Priti Patel is pushing ahead with plans to use force against boats carrying refugees across the Channel.
The Home Office is facing legal action over proposals to turn small boats around at sea, a tactic campaigners warn could put lives at risk.
“People seeking safety in the UK should be treated with compassion and dignity; this inhumane policy of pushbacks is unlawful, and we look forward to seeing the government in court,” said Mr Crawshaw.
“As this government knows all too well, this policy will only increase the risk of further loss of life.”
The latest attempts at the dangerous Channel crossing come despite sub-zero temperatures on the French coast.
At least 271 people aboard 10 small boats reached the UK on Thursday, including a young child.
So far this year, more than 450 people have made the life-threatening trip across the Channel in small boats following a record-breaking year in 2021.
A Home Office spokesperson said: “This tragic loss of life in France today is devastating and our thoughts are with the victim’s family and loved ones.
“It is sadly another reminder of the extreme dangers of crossing the Channel in small boats and of how vital it is that we work closely together with France to prevent people from making these dangerous crossings.”