He was born in Toulouse (there is some question about the exact year of birth), the son of a gymnastics instructor. He joined the Cirque Napoleon, and in November 1859 made his first public appearance as a trapeze artist, becoming the first to turn a somersault in mid-air and the first to jump from one trapeze to the next.
He invented and made famous a skin-tight one-piece garment with long sleeves, which he called a maillot, and wore it for his performances. It was designed to allow unrestricted movement, and to display his musculature. This garment made its way from the circus into the ballet studios of Paris. It is now known as a leotard: the first recorded use of this term in English was in 1886. (The French word maillot now means a swimsuit).
Jules Léotard died, aged about 30, of smallpox.