Louis Charrat was born on the 19th October 1903 in Fontaine-sur-Saone and appears to have spent most of his career in and around Lyons. He was a painter of portraits, interiors, still life and waterscapes. He entered the School of Fine Arts in Lyon in 1920 and was a student of Georges Décôte and Régis Deygas.
In 1931, he obtained the medal of honor from the Société Lyonnaise des Beaux-Arts and in 1934, he received the Prix de Paris at the Salon des Beaux-Arts, and the Prix Chenavard awarded by the École Nationale Supérieure des Beaux-Arts de Paris. He began exhibiting in Paris in 1934 at the Salon des Artistes Francais, who accepted him as a member in 1936 and awarded him a silver medal.
He designed the stained glass windows of the Saint-Bonaventure church in Lyon and in 1965 was elected a member of the Academy of Lyon. In 1969, he became president of the Société Lyonnaise des Beaux-Arts, succeeding Jean Dulac. He taught as a professor at the School of Fine Arts in Lyon from 1968 up to his death in 1971.