Charles Lapicque was born under the name of Charles René Thouvenin on October 6, 1898 in Theizé, in the Rhône, from a family originally from the Vosges. He is the adopted son of Louis Lapicque, professor of general physiology at the Faculty of Sciences in Paris, and Marcelle Lapicque, herself the daughter of Minister Severiano de Heredia. He spent his early childhood in Épinal and in 1900 made his first stay in Brittany, near Paimpol, where he returned for a long time each summer. He began studying the piano in 1903. From 1909 he lived in Paris where he attended his secondary studies, practiced drawing in high school and then in the free academies, in 1915 he began to practice the violin.
Mobilized from 1917 to 1919 in the field artillery, he acquired a knowledge of horses there which would later be found in his paintings and took part in the battles of 1918 and received the Croix de Guerre.