Rolls-Royce PLC's aerospace segment produces an extensive line of civilian and military aircraft engines, both alone and in joint ventures with companies in Europe, the United States, and Japan. Major products include the Trent and RB211 turbofan families (see jet engine) used on Boeing (Boeing Company), Airbus (Airbus Industrie), and Tupolev aircraft and the EJ200 turbofan developed for the Eurofighter Typhoon. Rolls-Royce is the world's leading supplier of marine propulsion equipment. Its products and services range from complete ship design to integrated propulsion, maneuvering, and positioning systems and deck machinery. Other nonaerospace products include aerospace-derived gas turbines (gas-turbine engine) for the oil and gas industries and power-generation plants and nuclear power systems for the Royal Navy.

The English engineer Frederick Henry Royce (Royce, Sir Henry, Baronet) established F.H. Royce and Co. in 1884 (renamed Royce Ltd. in 1899) to manufacture dynamos, electric motors, and electric cranes. He built his first motor car in early 1904. Soon thereafter he met Charles Stewart Rolls (Rolls, Charles Stewart), whose company, C.S. Rolls and Co. (founded in 1902), sold quality cars. The two men forged a business alliance in which Rolls would have the exclusive right to sell Royce's cars, which would bear the name Rolls-Royce. The success of the cars led to the formation of Rolls-Royce Ltd. in 1906 and the launch of its six-cylinder “40/50 hp” automobile. Later named the Silver Ghost (produced from 1907–25), the automobile earned a reputation as the “best car in the world” by the British motoring press. The company's success continued with such descendant models as the Twenty (1922–29), the several Phantoms (begun in 1925 and specially made for heads of state from 1949 onward), the Silver Wraith (introduced in 1947), and the Silver Dawn (1949) and, later, with models that included the Silver Cloud (1955), Silver Shadow (1965), and Silver Seraph (1998). In 1931 Rolls-Royce acquired Bentley Motors Ltd. (founded in 1920 by Walter Owen Bentley), a maker of fine cars, whose models thereafter gradually took on mechanical and design characteristics identical, except for minor details, to those of the Rolls-Royce line. For decades Rolls-Royce produced only the chassis and engines for its cars, leaving it to expert coach builders to construct coachwork to individual customer requirements. In 1939 it began making entire cars.

In 1914 Rolls-Royce produced its first aircraft engine, the Eagle. Its water-cooled Merlin engine, introduced on the eve of World War II, powered many aircraft (including the Supermarine Spitfire and the Hawker Hurricane) and became one of the most successful piston engines of that war. In the early 1940s, building on the pioneering jet propulsion work of English aviation engineer Frank Whittle (Whittle, Sir Frank), Rolls-Royce designed the Welland, the first jet engine to enter military service (in the Gloster Meteor in 1944). In 1953 the company's Dart turboprop engine, developed for the Vickers-Armstrongs Viscount, was the first turboprop to enter commercial service. In 1966 Rolls-Royce acquired Bristol Siddeley Engines (created in 1959 through the merger of Bristol Aero Engines and Armstrong Siddeley Motors), which at that time was developing the Pegasus vectored-thrust engine for the Harrier vertical/short-takeoff-and-landing jet fighter and the Olympus engine (with France's SNECMA) for the Concorde supersonic airliner. Eventually Rolls-Royce's jet-engine operations came to constitute, by far, the largest portion of the company in terms of sales.

Martin Bennett, Rolls-Royce & Bentley: The History of the Cars (1996, reissued 1998), discusses the models of the automobiles chronologically beginning with the first Royce cars of 1904 and continuing through 1996. Malcolm Bobbitt, Rolls-Royce & Bentley: Sixty Years at Crewe (1998); and Martin Bennett, Rolls-Royce and Bentley: The Crewe Years, 2nd ed. (1999), are comprehensive histories of the carmaker and its products from the end of World War II to the late 1990s.