Alberto Santos-Dumont (self-stylised as Alberto Santos=Dumont; 20 July 1873 – 23 July 1932) was a Brazilian aeronaut, sportsman, inventor, and one of the few people to have contributed significantly to the early development of both lighter-than-air and heavier-than-air aircraft. The heir of a wealthy family of coffee producers, he dedicated himself to aeronautical study and experimentation in Paris, where he spent most of his adult life. He designed, built, and flew the first powered airships and won the Deutsch prize in 1901, when he flew around the Eiffel Tower in his airship No. 6, becoming one of the most famous people in the world in the early 20th century.

Santos-Dumont then progressed to powered heavier-than-air machines and on 23 October 1906 flew about 60 metres at a height of two to three metres with the fixed-wing 14-bis (also dubbed the Oiseau de proie—"bird of prey") at the Bagatelle Gamefield in Paris, taking off unassisted by an external launch system. On 12 November in front of a crowd, he flew 220 metres at a height of six metres. These were the first heavier-than-air flights certified by the Aeroclub of France, the first such flights officially witnessed by an aeronautics recordkeeping body, and the first of their kind recognised by the Fédération Aéronautique Internationale.

Santos-Dumont is a national hero in Brazil, where it is popularly held that he preceded the Wright brothers in demonstrating a practical aeroplane. Numerous roads, plazas, schools, monuments, and airports there are dedicated to him, and his name is inscribed on the Tancredo Neves Pantheon of the Fatherland and Freedom. He was a member of the Brazilian Academy of Letters from 1931 until his suicide in 1932.

Alberto Santos-Dumont was the sixth child of Henrique Dumont, an engineer who graduated from the Central School of Arts and Manufactures in Paris, and Francisca de Paula Santos. The couple had eight children, three sons and five daughters: Henrique dos Santos-Dumont, Maria Rosalina Dumont Vilares, Virgínia Dumont Vilares, Luís dos Santos Dumont [pt], Gabriela, Alberto Santos-Dumont, Sofia, and Francisca. In 1873, the family moved to the small town of Cabangu, in the municipality of João Aires, for Henrique Dumont to work on the construction of the D. Pedro II railroad. The construction work finished when Alberto was 6, and the family moved to São Paulo. Here he began to show signs of his aeronautical interest; according to his parents, at the age of one he used to puncture rubber balloons to see what was inside. He was baptised in Valença at the Matriz de Santa Teresa [pt] on 20 February 1877, by Teodoro Teotônio da Silva Carolina.

In 1879, the Dumonts sold their farm in Valença, Rio de Janeiro, and settled in Sítio do Cascavel, in Ribeirão Preto, where they bought the Arindeúva Farm, of José Bento Junqueira, producing 1200 bushels of coffee. Until he was 10, he was taught by his older sister, Virginia. From 10 to 12 years old he studied at Colégio Culto à Ciência. He then attended Colégio Kopke in São Paulo, Colégio Morton, and Colégio Menezes Vieira in Rio de Janeiro, and later the School of Engineering from Minas, without finishing the course. He was not considered an outstanding student, studying only what interested him, and extending his studies independently in his father's library. By this time he already displayed the refined manners that would later become part of his image in France, and an introverted personality. He saw his first human flight in São Paulo at the age of 15, in 1888, when the aeronaut Stanley Spencer ascended in a spherical balloon and parachuted down. After a family trip to Paris in 1891, he became interested in mechanics, especially the internal combustion engine. From then on, he never stopped searching for alternatives, receiving from the City Council of Ribeirão Preto, according to Law no. 100, of 4 November 1903, a million réis subsidy to continue his researches that, three years later, resulted in the creation of his aeroplane. A newspaper of the time stated that Santos-Dumont would only accept if "...that amount was intended for an aircraft contest prize."

Santos-Dumont would remember with nostalgia the times spent on his father's farm, where he enjoyed the greatest freedom:

I lived a free life there, which was indispensable to form my temperament and taste for adventure. Since childhood I had a great love for mechanical things, and like all those who have or think they have a vocation, I cultivated mine with care and passion. I always played at imagining and building little mechanical devices, which entertained me and earned me high regard in the family. My greatest joy was taking care of my father's mechanical installations. That was my department, which made me very proud.

At the age of seven Santos-Dumont was already driving the farm's trains, and at twelve he could operate a locomotive on his own, but the speed achievable on land was not enough for him. By observing coffee machines he deduced that oscillatory machines wore out more, while those with circular motion were more efficient.