After his studies at the École nationale des chartes, Louis de Mas Latrie became an historian and specialized on Cyprus during the Middle Ages.

In 1848, he succeeded Jacques-Joseph Champollion as professor of diplomatics at the École de Chartes and held that position until his retirement in 1885.

His works won numerous awards, including a prize bt the Academy des Inscriptions in 1843, a medal in the competition of National Antiquities in 1850 and first and second Grand prix Gobert in 1862 and 1878.

In 1875, Pope Pius IX granted Louis Mas Latrie the title of count, transmissible to his male offspring.

One of the granddaughters of Louis Mas Latrie, Anne (1878–1946), married the royalist polemicist Roger Lambelin.