Charles Louis Antoine Pierre Gilbert Pineton de Chambrun was born in Paris.

Chambrun trained as a lawyer and was appointed in 1892 to replace his brother as legal council at the French embassy in the United States.

Chambrun returned to the United States in 1917 as a member of René Viviani's diplomatic mission and again in 1925 with Joseph Caillaux to discuss French war debts.

During the Second World War, in June 1940, he was the only senator to vote against the abolition of the French constitution and was one of the eighty members of the French parliament who voted against the grant of special powers to Philippe Pétain and the creation of the Vichy régime.

In 1947 he received the Croix de guerre 1939-1945 for his work during the Second World War and was made a Chevalier of the Légion d'honneur.