His father, also named François de Fossa, was one of the most important historians of the province of Roussillon.
De Fossa was born in Perpignan, the capital of Pyrénées-Orientales in southern France along the border with Spain.
At age 17, he joined an army regiment, the Légion de Pyrénées, which fought the revolutionary government in France.
A friend of Dionisio Aguado, he cooperated in his guitar method, also arranging its publication in Paris.
In 1826, the Paris firm of Richault published de Fossa's three guitar quartets, opus 19.