The 1978 Tour de France was the 65th Tour de France, taking place June 29 to July 23, 1978. The total race distance was 22 stages over 3908 km, with riders averaging 36.084 km/h. It was won by debutant Bernard Hinault, for the first of his five victories.

The following 11 teams each sent 10 cyclists, for a total of 110:

Since the 1977 Tour de France, dominant riders as Eddy Merckx, Felice Gimondi, Raymond Poulidor and Luis Ocaña had retired.

Lucien Van Impe, the winner of 1976, had broken his collarbone and was still recovering.

The main contenders were debutant Hinault, who had won the 1977 Vuelta a España, and Joop Zoetemelk, who had already finished in second place for three times. Pre-race analysis judged Hinault better in the time trials, and Zoetemelk better in the mountains.Bernard Thévenet, the winner of the 1977 Tour de France, was out of form, and not considered a favourite.

During the prologue, held in the Netherlands, the weather was bad. The four top places were taken by Dutch cyclists, with Jan Raas the winner. The team directors then had a meeting, and all but the manager of Raas' team voted to request the Tour direction to not count the results from the prologue for the overall classification. The direction agreed, so the prologue results did not count. Jan Raas was still given the stage win, but he was not recognized as race leader, so he was not allowed to wear the yellow jersey during the first stage. The winner of the previous year, Bernard Thévenet, was allowed to wear the yellow jersey, but he refused.

The Tour de France (French pronunciation: [tuʁ də fʁɑ̃s]) is an annual bicycle race held in France and nearby countries. First staged in 1903, the race covers more than 3,600 kilometres (2,200 mi) and lasts three weeks. As the best known and most prestigious of cycling's three "Grand Tours", the Tour de France attracts riders and teams from around the world. The race is broken into day-long segments, called stages. Individual times to finish each stage are aggregated to determine the overall winner at the end of the race. The rider with the lowest aggregate time at the end of each day wears the leader's yellow jersey on the next day of racing. The course changes every year, but the race has always finished in Paris. Since 1975, the climax of the final stage has been along the Champs-Élysées.

The tour typically has 21 days of racing and covers 3,200 kilometres (2,000 mi). The shortest Tour was in 1904 at 2,420 kilometres (1,500 mi), the longest in 1926 at 5,745 kilometres (3,570 mi). The three weeks usually include two rest days, sometimes used to transport riders from a finish in one town to the start in another. The race alternates between clockwise and anticlockwise circuits of France. The first anticlockwise circuit was in 1913. The New York Times said the "Tour de France is arguably the most physiologically demanding of athletic events." The effort was compared to "running a marathon several days a week for nearly three weeks", while the total elevation of the climbs was compared to "climbing three Everests."

France (English ⁱ/ˈfræns/ FRANSS or /ˈfrɑːns/ FRAHNSS; French: [fʁɑ̃s] ( listen)), officially the French Republic (French: République française [ʁepyblik fʁɑ̃sɛz]), is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean. It is often referred to as l’Hexagone ("The Hexagon") because of the geometric shape of its territory. It is the largest western European country and it possesses the second-largest exclusive economic zone in the world, covering 11,035,000 km² (4,260,000 sq mi), just behind that of the United States (11,351,000 km² / 4,383,000 sq mi).

Over the past 500 years, France has been a major power with strong cultural, economic, military and political influence in Europe and around the world. During the 17th and 18th centuries, France colonised great parts of North America and Southeast Asia; during the 19th and early 20th centuries, France built the second largest colonial empire of the time, including large portions of North, West and Central Africa, Southeast Asia, and many Caribbean and Pacific Islands.

Bernard Hinault (born 14 November 1954 in Yffiniac, Brittany) is a former French cyclist known for five victories in the Tour de France. He is one of only five cyclists to have won all three Grand Tours, and the only cyclist to have won each more than once. He won the Tour de France in 1978, 1979, 1981, 1982 and 1985. He came second in 1984 and 1986 and won 28 stages, of which 13 were individual time trials. The other four to have achieved at least five victories are Jacques Anquetil (1964), Eddy Merckx (1974), Miguel Indurain (1995) and Lance Armstrong (2003). Even among these elite riders, he is the only one to have finished either first or second in each Tour de France he finished.

Hinault was nicknamed Le Blaireau, initially for his looks, as he would often don a hairband, thus resembling a shaving brush. Later, the second meaning of this french word (the Badger) would become the dominant reason for his nickname, because the animal has the reputation of not letting go of his prey. Throughout his career, he's been known for his personality: independent, outspoken, quick to take offense and quick with a riposte. In an interview in the French magazine, Vélo, however, Hinault said the nickname had nothing to do with the animal. He said it was a local cyclists' way of saying "mate" or "buddy" in his youth - "How's it going, badger?" - and that it came to refer to him personally.

Michel Pollentier (born 13 February 1951 in Diksmuide, West-Vlaanderen) is a Belgian former professional road bicycle racer. He became professional in 1973. The highlight of his career was his overall win in the 1977 Giro d'Italia.

In the 1978 Tour de France, he was the Belgian national champion when he won the stage arriving in Alpe d'Huez and took the yellow jersey. However, he was accused of foul play in the succeeding doping test, having used what was described politely as a pear-shaped tube (in fact a condom) of different urine held under the armpit and connected by a plastic tube to give the impression of urinating. Pollentier was uncovered after another rider at the test had trouble operating his own system of tubes and aroused the suspicion of the doctor, who then demanded Pollentier lift his jersey to show if he too was cheating.

He was put out of the Tour, later won by Bernard Hinault.

The affair took away most of Pollentier's credibility in international cycling. Even though he managed to win 1980s edition of the Ronde van Vlaanderen and he also came 2nd in the 1982 Vuelta a España. 1984 was his last professional season. After his cycling career, Pollentier became a car tyre garage owner and founded a cycling school.