Léon Morel-Fatio was born in Rouen. His family came from the canton of Vaud (Switzerland). They moved to Paris in 1823 , where he studied at the Lycée Bourbon (former Lycée 6 Condorcet). Léon Morel-Fatio embarked on May 25, 1830, for the Algiers expedition under the command of Admiral Duperré. This trip was a turning point for young Morel-Fatio. He decided to become a painter after socializing with Pierre Julien Gilbert, the official painter of the expedition , Théodore Gudin and Eugène Isabey. Back in Paris, Léon Morel-Fatio trained with Eugène Devéria. He met in his studio Fabre, Bouchet, Aubert, Marquis, Saunier, Glaize, Doussautti and Augier.
His first contributions to the Paris Salon dated from that period. He mainly drew his inspiration from the trips he undertook. He first stood out through orientalist paintings. His fame grew during the July Monarchy. King Louis-Philippe I commissioned to Léon Morel-Fatio a Combat naval dans la baie d’Algésiras to adorn the historic galleries housed in the Versailles Palace and bought, at the following Paris Salon, a seascape Côte de Bretagne, destroyed during the burning of the Tuileries Palace in 1871.
The marquess Philippe de Chennevières, curator at the musée du Luxembourg, recorded in his journal: "officials commissions rained down on him when it came to represent historic maritime combats in painting for the Palace of Versailles (…)". Léon Morel-Fatio won the third son of Louis-Philippe, François d’Orléans, Prince de Joinville’s affection, and accompanied him during the Mexican Expedition in 1838. Léon Morel-Fatio painted accurate detailed descriptions of sailing maneuvers and also the lifestyle of sailors. At the Paris Salon, he gained recognition from his peers and won many medals. Léon Morel-Fatio was appointed Chevalier de la Légion d’Honneur, on July 5, 1846. During the Second Empire, Léon Morel-Fatio pursued a brilliant career, close to the Imperial Bonapartist regime. He was rewarded with a position as curator at the Paris maritime museum.