Pergaud was born on the 22nd January 1882, in Belmont, Doubs. Son of a republican schoolmaster, Louis was encouraged to excel in his studies. His academic successes earned him scholarships permitting him to continue school with the intention of following in his father's footsteps. In 1901, after completing his studies at the École Normale in Besançon, Louis Pergaud accepted his first teaching position in Durnes. He had only been teaching for one year when he was called to complete a year of military service with the 35th infantry regiment stationed in Belfort. In the fall of 1903, Pergaud returned to his post in Durne. He also married his first wife in that year. In 1905 Pergaud transferred to Landresse, a village that would eventually become so dear to his heart. Initially though, life in this small, isolated village was difficult for him because he found himself in conflict local people over certain major political issues of the time, the separation of Church and State to name one. In 1907, Pergaud left Landresse, and his wife, for Paris, where he joined a long time friend and inspiration, Leon Deubel. In Paris, Louis Pergaud suffered through extreme poverty, even as he worked as a clerk and then as a schoolteacher, in an effort to realize his dream of literary success.

His earliest works were collections of poetry that were published at his own expense through a literary review called Le Beffroi. The first collection, entitled L'Aube, appeared in 1904. The second, L'Herbe d'Avril, was published in 1908. In 1910 Mercure de France published a collection of Pergaud's short stories under the title De Goupil à Margot. This work earned for the author the prestigious Prix Goncourt which lead to a certain amount of national recognition. A second collection of short stories about animals, La Revanche du corbeau appeared in 1911. "La Guerre des boutons", described below, was published in 1912. In 1913 Pergaud produced another novel, Le Roman de Miraut, once again giving an animal the leading role. He wrote numerous other short stories about the people and animals of his native Franche-Comté that would be published posthumously.

In 1912 La Guerre des boutons was published, a tale of a play-war between the small boys of two neighbouring villages. Those "killed" would have their buttons removed as trophies before being sent home. The novel begins humorously and harmlessly, but becomes more sinister as the distinctions between play-war and real violence become blurred. It has been described as having a "touch of Lord of the Flies" in tone, although the book obviously substantially pre-dates that novel. Pergaud's works remain popular in France, with the La Guerre des boutons having been reprinted over thirty times. There is a Paris society especially devoted to him and his works, named Les Amis de Louis Pergaud.

Despite his pacifism, Louis Pergaud was conscripted into the French Army at the outbreak of the First World War, having been placed in the active reserve following his national service twelve years before. In this capacity he served in the Battle of Lorraine during the German invasion of France and subsequently on the Western Front. On 7 April 1915, Pergaud's regiment launched an attack on German lines near Fresnes-en-Woëvre, in which Pergaud was shot and wounded, falling into barbed wire and becoming trapped. Some hours later, German soldiers rescued him and took him and his comrades to a temporary field hospital behind their lines. It was there, on the morning of the 8 April, that Pergaud was killed in a French artillery barrage that destroyed the hospital.

La Guerre des boutons has been made into a film three times:

• La Guerre des Gosses (1936, France) by Jacques Daroy
• La Guerre des Boutons (1962, France) by Yves Robert
• War of the Buttons (1994, Ireland) by John Roberts