Born in Les Sables-d'Olonne, Launois showed a gift and passion for drawing. His parents encouraged him, but his formal training was limited to working with Charles Milcendeau and later Auguste Lepère. He briefly attended the Ecole Julian in Paris. Launois produced numerous sketches, drawings and paintings during and after the First World War.

On December 15, 1916, Launois enlisted in the horse artillery rather than wait for his "age group" to be drafted. Documentation of his military service is scarce, but he saw action on the Western Front during the winter, spring and summer of 1917. At the end of December 1917, his division was sent to the Eastern Front, where he fought again. During this period, Launois created numerous sketches and studies of French soldiers.

Even before demobilization at the end of 1918, Launois returned on leave to his family home in Tour. His father took him to Paris and introduced him to the assistant curator of the Musée du Palais du Luxembourg. Launois showed him his portfolio of drawings made during his military service. The museum's curator, Léonce Bénédite, receives authorization from the Under-Secretary for the Arts to buy 12 drawings by Launois for 500 francs. Still at Tour, Launois creates a portrait of Anatole France that is well received, widely distributed and published in the newspaper L'Illustration.

Later, Bénédite buys other drawings by Launois and encourages him to compete for the Bourse de l'Algérie. He won the scholarship, which came with a two-year allowance (room, board and a little money) at the Villa Abed-el-Tif in Algiers.

In Algeria, he met Fréderic Lung and Mesley, two serious collectors who bought many of his paintings. He also met and traveled south with Albert Marquet and his future wife, with whom he established a deep and lasting friendship.

In 1923, Launois won the Prix de l'Indochine of 3,000 francs, which included a trip from France to Saigon. His stay in Indochina is well documented in his letters. He crossed the Indochinese peninsula on foot, on horseback and by boat, sailed down the Mekong on the private raft of a Laotian prince and traveled by rail from Hanoi to China and back. During his travels, Launois documented his experiences with drawings and sketches that included forest natives and life in villages and bars.

In the late 1920s, Launois traveled frequently between Paris, the Vendée and Algeria. His first major exhibition in 1926 was a great success. He also illustrated books for Roland Dorgèles, Francis Carco and Octave Mirbeau. In 1927, Launois married Aimée Suarès Lévy, the niece of poet André Suarès. While his artistic success continued, his marriage was undermined by his independent, free-spirited personal life, excessive alcohol consumption and association with the Parisian underworld.

In 1933, with the collapse of the economy, life became difficult for the Launois family. Faced with these difficulties, his parents-in-law sold their Paris apartment. Although living from hand to mouth, Launois continued to travel from Paris to North Africa in winter, and in summer to Saint-Jean-des-Monts, where he ran an informal art school.

In 1939, with the declaration of war between France and Germany, Launois was mobilized. His health was poor, with swollen legs and eczema. After the intervention of well-placed friends, he was relieved of his most onerous duties and reassigned to a camouflage unit. In the late 1940s, after the end of the war, he moved into his in-laws' house in Saint-Tropez, where he met up with old friends and continued to paint and exhibit.

Launois returned to Algeria in March 1942. His health was fragile and he drank heavily. His friends took care of his needs. On November 22, 1942, he collapsed in a small park in front of the hotel where he was staying in Algiers, and was taken to his room where he died.

The Musée de l'Abbaye de la Sainte-Croix in Les Sables d'Olonne holds an important collection of his paintings, drawings and documents. Launois' drawings, purchased by the Musée du Palais du Luxembourg, are now part of the collection of the Musée d'Art Moderne in Paris.