Delangle was born on 15 December 1901 in Aunay-sous-Auneau, a village forty miles from Paris. Her father was the local postman. At three years old she witnessed the catastrophic 1903 Paris–Madrid race passing near her village. She moved to Paris in 1918 and worked as a nude model and dancer, eventually performing at the Hôtel Ritz and the Olympia Hall alongside dance partner Celéstin Eugène Vandevelde under the stage name Hellé Nice. By 1927 she was prominent enough to appear at the Casino de Paris in a show headlined by Maurice Chevalier. A skiing accident at Megève damaged the cartilage in her knee and ended her dancing career; she turned to motor racing, managing the pain with morphine.
Nice entered her first major race, the Grand Prix Féminin, in June 1929 at the Autodrome de Linas-Montlhéry. Driving an Oméga-Six, she won. The following day Ettore Bugatti invited her to drive a Type 43A in the Actor's Championship, which she also won. She quickly signed a sponsorship deal with Lucky Strike cigarettes and purchased a yacht and a Hispano-Suiza car. Bugatti then invited her to speed trials at Montlhéry, where in December 1929 she recorded 196.871 km/h over five kilometres — a remarkable benchmark for a woman of that era.
In 1930 she toured the United States, performing as an exhibition dirt-track driver at venues including Langhorne Speedway. Promoted as the "Speedbowl Queen" and sponsored by Esso, she was billed as the first woman to race on American dirt tracks. She returned to Europe and continued racing through the early 1930s, competing at Reims, Monza, Le Mans, Comminges, and Casablanca, often as the sole female entrant against established male professionals including Louis Chiron, René Dreyfus, and Philippe Etancelin.
In 1932 she won the Rallye Paris–Saint-Raphaël Féminin with co-driver Odette Siko in an Alfa Romeo 6C. She also competed in the Algerian Grand Prix at Oran, finishing second in the 2-litre category. During 1937 she participated in Yacco oil endurance trials at Montlhéry alongside Claire Descollas, Simone des Forest, and Odette Siko, driving a Matford V8 car continuously for ten days and ten nights, with the team breaking ten world records.
In 1936 Nice travelled to Brazil to compete in two Grand Prix events. During the São Paulo Grand Prix, while running in third place, her Alfa Romeo hit a hay bale and crashed into the grandstand, killing six spectators and injuring more than thirty others. Nice was thrown from the car, landing on a soldier who also died; she was unconscious and initially presumed dead. She spent three days in a coma. Brazilian President Getúlio Vargas visited her in hospital. She was not held legally responsible for the accident, and she later returned to racing in Europe.
Nice sat out much of World War II in the south of France. In 1949, at a Monaco party celebrating the first postwar Monte Carlo Rally, the noted racing driver Louis Chiron publicly accused her without evidence of having been a Gestapo informant during the war. The allegation was investigated — her biographer Miranda Seymour later found no record of collaboration in the German Federal Archives in Berlin — but sponsors withdrew and her planned racing comeback collapsed. She was prevented from starting the 1951 Nice Grand Prix at the last moment, replaced by a young Jean Behra.
Nice lived in poverty after the accusation ruined her career. Her partner Arnaldo Binelli left her in 1960. She was supported by the charity La Roue Tourne and worked as a chauffeur. She died in Nice in September 1984 after falling into a coma following an operation. Her ashes were returned to Sainte-Mesme, where her estranged sister refused to engrave her name on the family gravestone.
Miranda Seymour's 2005 biography The Bugatti Queen rehabilitated her reputation. In 2010 the Hellé Nice Foundation installed a commemorative plaque on her grave. A 1927 Bugatti Type 35B she had owned sold at the Pebble Beach Concours d'Elegance in 2014 for $2,970,000.