Louis Delage founded the company in 1905, borrowing 35,000 francs and giving up a monthly salary of 600 francs to do so. The first workshop on the Rue Cormeilles in Levallois-Perret started with just two lathes and three employees — one of them Peugeot's former chief designer. The first production model was the 1906 Type A voiturette, powered by a one-cylinder De Dion-Bouton engine of 4.5 or 9 horsepower.
Racing came almost immediately. In November 1906, Delage entered the Coupe de Voiturettes at Rambouillet. By 1908, victory arrived: Delage won the Grand Prix des Voiturettes at Dieppe on 6 July, with works driver Albert Guyot taking the chequered flag in a radical single-cylinder 1,257cc car at an average 49.8 mph over six laps of the 47.74-mile circuit. All three Delages entered finished the race, and the team also took the regularity prize — a strong signal of the constructor's potential.
Delage moved up to full Grand Prix racing in 1912, commissioning a Léon Michelat-designed four-cylinder of 6,235cc and 118 horsepower. At the Amiens Grand Prix, Bablot's Delage proved the fastest car in the field, though a Peugeot eventually won. That same year at the French Grand Prix, Delage placed Bablot first among a competitive field.
In 1913, a new Delage set the fastest lap at the French Grand Prix at Le Mans, and in 1914 René Thomas won the Indianapolis 500 at the wheel of a Delage — one of the most prestigious international victories the marque would achieve. Twin-cam desmodromic-valve racers were fielded at the 1914 French Grand Prix, though reliability limited their results.
The 1920s represented Delage's peak in Grand Prix competition. In 1923, Louis Delage returned to racing with a 12-cylinder 2-litre type 2 LCV. This car won the 1924 European Grand Prix in Lyon and the 1925 Grand Prix of the ACF at Montlhery. A V12 development of 10,688cc broke the course record at the Gaillon hillclimb in 1924 with Thomas at the wheel, and Thomas subsequently set the land speed record at Arpajon at 143.24 mph (230.52 km/h).
For 1926, a new Lory-designed supercharged 1.5-litre twin-cam straight-eight produced 170 horsepower and was capable of 130 mph. That year a Delage 155 B won the first British Grand Prix, driven by Louis Wagner and Robert Senechal. In 1927, the 8-cylinder 1500cc type 15 S 8 won four European Grand Prix races, earning Delage the title "World Champion of Car Builders." It was the summit of the company's racing achievement.
Alongside its competition programme, Delage built a range of prestigious road cars. The most celebrated was the D8, launched in 1930, powered by a 4,061cc straight-eight engine and capable of 85 mph. The Grand Sport variant on a shorter wheelbase could reach 100 mph. The 1920s also saw the DI and DIS models — four-cylinder 2-litre touring cars that became the marque's best sellers — and the GL Grand Luxe, a six-cylinder flagship competing directly with Hispano-Suiza.
From 1927, Maurice Gaultier's DM and DMS six-cylinder models defined the marque's mid-range offering, the DR being particularly strong in sales. These were high-quality, expensive automobiles aimed at the top of the French luxury market.
The economic depression of the early 1930s hit the luxury car market hard, and Delage's finances were badly shaken. In 1932, Louis Delage was obliged to take out a 25 million franc loan to fund D6 production tooling. Negotiations with Peugeot about sharing a dealer network came to nothing. Personal financial difficulties compounded the commercial problems.
On 20 April 1935, the Courbevoie factory went into voluntary liquidation. Louis Delage refused to accept defeat entirely, partnering with businessman Walter Watney to create the Société Nouvelle des Automobiles Delage, which marketed Delage-badged cars assembled from Delahaye components. When Watney left France following the German occupation in 1940, control passed entirely to Delahaye. Louis Delage himself died in December 1947, having lived in poverty since the 1935 bankruptcy.
Postwar Delahaye-built Delages continued in small numbers until 1953, when production finally ended. The brand was absorbed into Hotchkiss along with Delahaye in 1954. A new Delage Automobiles was announced in 2019 under entrepreneur Laurent Tapie, with the D12 hybrid hypercar as its first model.