Louis "Louison" Bobet (pronounced [lwi.zɔ̃ bɔ.be]; 12 March 1925 – 13 March 1983) was a French professional road racing cyclist. He was the first great French rider of the post-war period and the first rider to win the Tour de France in three successive years, from 1953 to 1955.

Louis Bobet was born one of three children above his father's baker's shop in the rue de Montfort, Saint-Méen-le-Grand, near Rennes. His father gave him a bicycle when he was two and after six months he could ride it 6 km. Bobet's father was also called Louis and the son was called Louison – little Louis – to avoid confusion The ending -on is a diminutive in French but outside Brittany Louison refers more usually to a girl. He was known as Louis in his early years as a rider, even as a professional, until the diminutive Louison gained in popularity.

His sister played table tennis, his brother Jean football, although he also became a professional cyclist. Louison played both table tennis and football and became Brittany champion at table tennis. It was his uncle, Raymond, who was president of a cycling club in Paris who persuaded him to concentrate on cycling.

Bobet's first race was a 30 km event when he was 13. He came second in a sprint finish. He raced in his local area and won four events for unlicensed riders in 1941. He qualified for the final of the unofficial youth championship, the Premier Pas Dunlop in 1943 at Montluçon and came sixth. The winner was Raphaël Géminiani, who would become a professional team-mate and rival.

Bobet is said to have carried messages for the Resistance during the Second World War. After D-Day he joined the army and served in eastern France. He was demobilised in December 1945.

Bobet applied for racing licence on leaving the army and by error was sent one for an independent, or semi-professional. He benefited from the right to compete against professionals as well as amateurs. He came second in the Brittany championship and rode the national championship in Paris. There he came up against a veteran professional, Marcel Bidot, who on retirement became Bobet's manager in the national team. Bobet left the field to catch two riders who had broken clear. He dropped one and outsprinted the other to become national champion. He turned fully professional for Stella, a bicycle factory in Nantes.

Stella was a small team that rode mainly in Brittany. In May 1947, however, two from the team rode the Boucles de la Seine race in Paris. He won alone by six minutes. It brought him an invitation to ride the Tour de France, at that time disputed by national and regional teams. The unexpected toughness of the race forced him to go home on the ninth day, in the Alps and to cry when the going got hard. It brought him the nickname "cry-baby" in the bunch and René Vietto referred to him as La Bobette, a mock feminisation of his name, for his tears and complaining. The historian Dick Yates wrote:

The former rider, Maurice Archambaud, took over management of the team from Léo Véron and took a chance on Bobet. Much had changed since the previous summer and he took the lead after the third stage, which finished near Stella's factory in Nantes. Bobet lost the yellow jersey the following day but regained it by winning the sixth stage, to Biarritz. He had 20 minutes' lead over the veteran Italian, Gino Bartali as the race entered the Alps. And then happened one of the most outstanding periods in the history of the Tour.