The Le Mans 24 Hours, scheduled to take place on 13-14 June, has been postponed and rearranged for 19-20 September because of the coronavirus outbreak.
Organisers say it is the "appropriate solution" in the circumstances.
"Today it is a question of stopping the spread of this virus," Pierre Fillon, president of the Automobile Club de l'Ouest (ACO), said on Wednesday.
Fernando Alonso won the race for the second consecutive year in 2019 with Toyota.
The postponement will also mean changes to several other motorsport events this year - including the European Le Mans Series, the Michelin Le Mans Cup and the Ligier European Series.
The ACO said it would announce further details on those calendar changes, along with a full timetable for Le Mans.
"It goes without saying that we will make every effort to ensure the safety and quality of our events, " Fillon added.
"First of all, I want to ask everyone to take no risk for themselves, their families and others. I would also like to spare warm thoughts for all the medical personnel working to protect our health.
"We are more than ever working as one team together with our competitors, partners, fans, media, medical services, organisation teams and marshals."
Also in the motorsport world, the IndyCar Grand Prix of Long Beach - scheduled for 19 April - was cancelled because of the pandemic. The race will return in 2021.