Louis Claude Rosier (5 November 1905 – 29 October 1956) was a French racing driver and motorsport executive, who competed in Formula One from 1950 to 1956.

Rosier competed in Formula One under his own Écurie Rosier banner, making privateer entries in machinery from Talbot-Lago, Ferrari, and Maserati; he also competed for the works teams of Talbot and Maserati, the former of which he scored back-to-back podium finishes with at the Swiss and Belgian Grands Prix in 1950.

In October 1956, Rosier died as a result of injuries sustained whilst sportscar racing in a Ferrari 750 Monza at Montlhéry.

He won the Dutch Grand Prix twice in consecutive years between 1950 and 1951, the Circuit d'Albi, Grand-Prix de l'Albigeois and the 24 Hours of Le Mans with his son Jean-Louis Rosier.

Stirling Moss drove a blue Maserati to victory in the 67-lap event for Formula One cars, with an average speed of 84.24 miles per hour (135.57 km/h).

Throughout the 1950s, Écurie Rosier provided drives in Formula One for Henri Louveau, Georges Grignard, Louis Chiron, Maurice Trintignant, André Simon and Robert Manzon.

[11] A set of preliminary designs were drawn up for a circuit of a length between 4 and 6 km, meeting the latest safety regulations with large parking capacity at a location just outside the city limits on a hilly landscape.

Auchatraire, Rosier and Raymond Roche (the manager of Reims-Gueux race track) worked together to get the project accepted by the political community before searching for funding.

The racetrack was opened on 27 July 1958, with the name of its famous founder "Circuit de Charade Louis Rosier".

[13][14] In 1953, using the concept of a barchetta that he raced at Le Mans,[15] Rosier, together with Italian coachbuilder Rocco Motto, designed a cabriolet,[16] still using 4CV Renault sub assemblies.

Some time later he designed a roadster using Renault Frégate elements with an aluminum body developed by Rocco Motto, on a multi-tubular frame.

[18] On 7 October 1956 Louis Rosier was competing in the Coupe du Salon sports car race at Montlhéry in a Ferrari 750 Monza.