Ettore Arco Isidoro Bugatti (September 15, 1881, Milan, died on August 21, 1947) was an automobile designer.

He came from a notably artistic family that had its roots in Milan. He was the elder son of Teresa Lorioli and her husband Carlo Bugatti (1856–1940), an important Art Nouveau furniture and jewelry designer. His younger brother was a renowned animal sculptor, Rembrandt Bugatti (1884–1916), his aunt, Luigia Bugatti, was the wife of the painter Giovanni Segantini, and his paternal grandfather, Giovanni Luigi Bugatti, was an architect and sculptor.

Before founding his own automobile company, Ettore designed a number of engines and vehicles for others. Prinetti & Stucchi produced his 1898 Type 1. From 1902 through 1904, Dietrich built his Type 3/4 and Type 5/6/7 under the Dietrich-Bugatti marque. In 1907, Bugatti went to work for the Deutz Gasmotoren Fabrik, designing the Type 8/9.

On his own time, Bugatti developed the Type 2 (in 1900 and 1901), and the 1903 Type 5. While at Deutz, Bugatti built his Type 10 in the basement of his home. In 1913, Bugatti designed a small car for Peugeot, the Type 19 "Bébé".

Although born in Italy, Bugatti was set up in Molsheim, in the Alsace region, now part of France. Ettore Bugatti was the technical innovator behind the company, developing a number of engines and chassis for the numerous models produced over the next three decades. The company was known for its advanced engineering in its premium road cars and its success in early Grand Prix motor racing, winning the first ever Monaco Grand Prix.

Ettore Bugatti also designed a successful motorized railcar, the Autorail, and an airplane, but it never flew. His son, Jean Bugatti, was killed on August 11, 1939 at the age of 30, while testing a Type 57 tank-bodied race car near the Molsheim factory. After that, the company's fortune began to decline. World War II ruined the factory in Molsheim, and the company lost control of the property. During the war, Bugatti planned a new factory at Levallois in Paris and designed a series of new cars.

Ettore Bugatti was interred in the Bugatti family plot at the municipal cemetery in Dorlisheim near Molsheim in the Bas-Rhin département of the Alsace region of France.