The 2020 course was held behind closed doors as part of the French government’s attempts to stem the spread of the coronavirus pandemic.
The 2021 race - scheduled to take place between 12 and 13 June - was also facing the prospect of unfolding in front of deserted stands.
“Holding the 24 Hours of Le Mans behind closed doors for the second year running would be unthinkable,” said Pierre Fillon, president of the Automobile Club de l’Ouest (ACO) which stages the race.
“We are therefore doing all we can to avoid that happening.”
The event will take place at the legendary Circuit de la Sarthe between 21 and 22 August.
“We are working very hard to put on a safe event, with all the necessary health precautions in place,” added Fillon.
The 24 Hours of Le Mans is one of six events in the World Endurance Championship which was set up in 2012.
The 2021 season is scheduled to start with the 8 Hours of Portimao in Portugal on 4 April at the Autódromo Internacional do Algarve.
The 6 Heures de Spa-Francorchamps in Belgium was also scheduled to precede Le Mans.
The campaign is due to culminate on 20 November at the 6 Hours of Bahrain.
“Although it was a tough decision to make, it is the right one,” added Fillon.
