The National Assembly approved the motion by 331 votes. A minimum of 288 were needed.
President Emmanuel Macron insisted he will serve the rest of his term until 2027. However, he will need to appoint a new prime minister for the second time after July’s legislative elections led to a deeply divided parliament.
Barnier, a conservative appointed in September, will become the shortest-serving prime minister in France’s modern Republic.
“As this mission may soon come to an end, I can tell you that it will remain an honor for me to have served France and the French with dignity,” Barnier said in his final speech before the vote.
“This no-confidence motion… will make everything more serious and more difficult. That’s what I’m sure of,” he said.