The 1979 24 Hours of Le Mans was the 47th Grand Prix of Endurance, and took place on 9 and 10 June 1979. With no other major works cars this year, the Porsche team were the strong favourites to win. Their competition would be from Cosworth-powered Mirages and Rondeaus and a swarm of Group 5 and IMSA-class Porsche 935s. The other big talking point was the presence of Hollywood actor Paul Newman, driving for Dick Barbour Racing.

However, the Porsche 936s ran into problems early, as did the Mirages that inherited the lead. The race became a duel between the 935s of the rival teams from Cologne: Kremer Racing and Gelo Sportswear. Soon after midnight, heavy storms started sweeping the circuit. The rain stayed for virtually the rest of the race, dramatically slowing the pace, negating the speed of the 936s coming back through the field. Both Gelo cars retired with mechanical issues in the soggy dawn, and when the Wollek/Haywood Porsche developed a bad misfire soon after it looked like the Kremer 935 of Klaus Ludwig and the Whittington brothers had the race covered. They had a 13-lap lead over the Dick Barbour Porsche.

Then approaching 11am Don Whittington came to a stop on the Mulsanne Straight with a broken drivebelt. It took 80 minutes to get back to the pits, and by the time they got back into the race their lead was down to four laps. But the charging American team were foiled by a faulty wheel-nut taking 23 minutes to fix. Then in the last hour, the car slowed with a bad misfire. Stommelen pulled up just before the finish line and waited for the Kremer car to take the flag in victory. The Kremer brothers' finest hour was sealed with their other team-car coming home in third.

Porsche finished 1-2-3-4, and the Kremer 935-K3 was the first Le Mans win by a rear-engined car. The torrential rain in the second half of the race made it the slowest Le Mans since 1958.

In April 1978, the sports regulatory body, the CSI, was overhauled and replaced by the new international racing organisation FISA. The World Championship for Makes was revised to include both Group 5 and Group 6 racecars again, split into two categories: over and under 2-litres. FISA President, Jean-Marie Balestre was committed to bringing Le Mans back into the World Championship, but for now the Automobile Club de l'Ouest (ACO) chose to remain independent.

A change to the circuit was forced upon the ACO this year. Construction of the city's ring-road system meant the second Dunlop Bridge at the Tertre Rouge corner had to be demolished. The right-hand corner that led onto the Hunaudières straight was eased into a faster double-apex corner, shortening the overall circuit length by 14 metres (46 feet) to 13.63 km. The only other change was to move the start-time forward two hours, to 2pm in Saturday, to allow the spectators more time on Sunday afternoon to vote in the first European parliament elections.

A new efficiency calculation was used this year – the Index of Fuel Consumption. The total fuel used was measured as at the final pit-stop and then gauged against the cars' total distance covered, as litres per 100 kilometres. It was not exact, as no account was taken of the remaining fuel in the tanks after the race, expecting no team would fill in way too much fuel, or not enough.

The ACO received 87 applications, from which 60 were accepted to qualify for the 55 starting spots. Porsche was the only manufacturer with a works team and made up 19 of the 55 starters. Entries again came from regular specialists Mirage, De Cadenet, Rondeau and WM. There were also exploratory entries from Formula 1 constructor March and the Japanese companies of Mazda and Dome.