The suspect is a 15-year-old boy and the deceased is a girl, report French media.
The boy attacked several other students with a knife during lunch break at 12:30. The student was eventually overpowered by teachers and arrested by the police.
The condition of one of the injured students is described as critical.
"Breaking down humanity"
The exact motive is unknown. However, the suspected boy is said to have sent a long, manifesto-like email to the school's students before the attack.
In it, he writes about how "globalization has transformed our system into a machine that breaks down humanity", according to AFP. He is also said to have expressed admiration for Adolf Hitler.
He was known to be depressed, he said he loved Hitler, says a girl at the school to AFP, and she also tells about the attack:
I was in the cafeteria with my friends and we heard that a high school student had stabbed students in several classrooms.
After the arrest, the suspect was, on the advice of psychiatrists, handed over to care, writes Le Figaro.
Macron praises the teachers
The school's students were kept indoors for a few hours after the attack. Later in the afternoon, they were escorted out in cooperation with the police to anxious parents who had gathered outside.
France's Education Minister Elisabeth Borne and Interior Minister Bruno Retailleau have both visited the school, according to Borne to show "solidarity with the victims".
President Emmanuel Macron writes in a statement on X that he is thinking of the victims and their families. He also thanks the teachers who intervened.
"Through their actions, the teachers likely prevented further tragedies."
The school is a private school with around 2,000 students.
