British engineer and designer of the Rolls-Royce car and aeroengines. He was made a baronet in 1930.

Born in Alwalton, Huntingdonshire, the son of a miller, Royce began his working life as a newspaper boy and telegraph messenger. In 1877 he began a three-year apprenticeship with the Great Northern Railway Works, Peterborough. Royce's first business ventures were selling small electrical devices of his own design. In this field he was just beginning to experience some success, manufacturing a dynamo of his own design, when his market collapsed under a flood of cheaper US and German imports. Searching for other markets to explore, Royce turned his attention to the motor car. His first car was ready for testing in 1904. One of Royce's early cars was shown to the Honourable Charles Rolls (1877-1910), the son of Lord Llangattock and winner of the Automobile Club's Thousand Mile Trial in 1900. So impressed was Rolls with the car that shortly afterwards, in 1906, they entered into the famous Rolls-Royce partnership. Royce was the engineer, Rolls the promoter. Their first major success was the Silver Ghost. Introduced in 1907, it remained in production for nineteen years. With a special expansion chamber for each cylinder, it demonstrated Royce's concern with silence, comfort, and reliability. For its production a new factory was opened in Derby, still the home of Rolls-Royce. The founder, however, saw little of this factory: Rolls was killed in a flying accident in 1910, while in the same year Royce's health collapsed and he was given three months to live. Told he must live by the sea and take things much easier, he never returned to his Derby factory, setting up drawing offices with his chief designers to work on his new models at homes in the south of France and at West Wittering on the south coast of England.

In addition to further work on the Silver Ghost, Royce began on the outbreak of World War I in 1914 to design a 12-cylinder water-cooled aeroengine. The result, the Eagle engine, was ready for testing in 1915 and was followed by the Hawk, Falcon, Condor, and Kestrel engines. Nearly 75 per cent of the aeroengines used in British aircraft during World War I were designed by Royce. A few months before his death he had started work on the Merlin, the engine that would later power the Spitfire in World War II. The design of this engine was continued by a team led by A. G. Elliott (1889-1978), an engineer whom Royce had himself trained and who later became the company's chief engineer and managing director.