Gustave Adolphe Clément was born in Pierrefonds, Oise, in 1855. Orphaned young, he trained as a blacksmith and completed the Compagnon du Tour de France, the traditional craftsmen's journey around France. He opened a bicycle repair business in Bordeaux in 1876 and by 1890 was the leading cycle brand in France. His acquisition of the French manufacturing rights for Dunlop pneumatic tyres in 1889 — for which he paid 50,000 francs — generated the fortune that funded his automotive ventures: the company paid 100 percent dividend in its first year of operation.
In 1896, Clément was a passenger in Albert Lemaître's Peugeot that was judged the official winner of what is considered the world's first motor race, the 1894 Paris–Rouen event. By 1898, his factories were building Clément-Gladiator cars at Levallois-Perret in northwest Paris.
Clément's automotive interests operated under several interlocking names. Clément-Gladiator built cars from 1898 at Levallois-Perret, with production exceeding 1,000 vehicles per annum by 1902. In 1902, the English arm was separately incorporated as Clément-Talbot Ltd, managed by Charles Chetwynd-Talbot. In 1903, Clément founded Clément-Bayard on a former military site at Mézières (now Charleville-Mézières), naming the company after the medieval knight Chevalier Pierre Terrail, seigneur de Bayard, who had saved the town from an Imperial army in 1521. A statue of Bayard stood in front of the factory, and his image appeared in the company logo.
Clément also invested one million francs in Panhard et Levassor in 1897, became a director of that firm, and manufactured Clément-Panhard cars at Levallois-Perret under licence from a design by Commandant Arthur Krebs.
Clément-Bayard entered major motor racing from 1904. Albert Clément, the founder's son, finished second at the 1904 Vanderbilt Cup on Long Island and won the 1904 Circuit des Ardennes des Voiturettes at Bastogne in 4 hours 26 minutes 52.6 seconds.
The company entered three cars for the inaugural 1906 French Grand Prix at Le Mans. Albert Clément finished third in a 100 hp machine, completing the 1,238 km event in 12 hours 49 minutes 46.2 seconds. He had led the race at the end of laps two and five on the second day before punctures, aided by Michelin's newly introduced detachable rim system, cost him time and allowed Felice Nazzaro's FIAT to take second place. Albert Clément also finished fourth at the 1906 Vanderbilt Cup.
Tragedy followed in 1907. Albert Clément died while practising for the 1907 French Grand Prix on 17 May. Of the other Clément-Bayard entries in that race, Pierre Garcet and Elliott Shepard finished seventh and eighth respectively. The founder never fully recovered from his son's death; by 1913 he had been elected mayor of Pierrefonds and ceded control of the company to his surviving son Maurice.
For the 1908 French Grand Prix, the company entered three cars using a 12,963 cc six-cylinder overhead camshaft engine; Victor Rigal finished fourth.
Clément-Bayard was an early French manufacturer of aircraft and airships. The company collaborated with Alberto Santos-Dumont in 1908 to build his Demoiselle No. 19 monoplane, producing 50 units — it was the world's first series production aircraft. Pierre Clerget designed a range of Clément-Bayard aero engines for the company, including a 4-cylinder 100 hp unit used on Hanriot Etrich monoplanes and a V8 200 hp airship engine.
In 1910, the Clément-Bayard No. 2 airship, piloted by Maurice Clément-Bayard, became the first airship to cross the English Channel, covering over 380 km in six hours. Seven Clément-Bayard airships were ultimately completed.
In 1900, Adolphe Clément-Bayard was among the leading anti-Dreyfusard industrialists, along with Comte Jules-Albert de Dion. Together they cancelled all advertising in the Dreyfusard newspaper Le Vélo and backed a rival daily sports paper, L'Auto-Vélo. That paper's subsequent history led directly to the founding of the Tour de France cycle race and ultimately to the creation of L'Équipe, the French national sports newspaper — consequences traced directly to Clément's political stance in the affair.
The First World War destroyed most of Clément's manufacturing empire. The La Macérienne factory at Mézières was occupied by German forces in the opening weeks, with industrial machinery shipped back to Germany. Automobile production at Levallois-Perret was suspended in August 1914 and converted to war production including aero engines and airships.
In 1922, the Clément-Bayard company was sold to André Citroën. The factory at Levallois-Perret subsequently became the centre of Citroën 2CV manufacturing for nearly four decades. Adolphe Clément died of a heart attack in Paris in 1928 while driving to a board meeting.