The original company, T.G. John and Company Ltd., was founded in 1919 by Thomas George John (1880–1946). Its first products were stationary engines, carburetors and motorscooters. On 14 December 1921 the company officially changed its name to The Alvis Car and Engineering Company Ltd. Geoffrey de Freville (1883–1965) designed the first Alvis engine and is also responsible for the company name.
Production was relocated to Holyhead Road in Coventry, where from 1922 to 1923 they also made the Buckingham car. In 1922 George Thomas Smith-Clarke (1884–1960) left his job as assistant works manager at Daimler and joined Alvis as Chief Engineer and Works Manager. Smith-Clarke was accompanied by William M. Dunn, who also left his job as a draughtsman at Daimler to become Chief Draughtsman at Alvis. This partnership lasted for nearly 28 years and was responsible for producing some of the most successful products in the company's history. Smith-Clarke left in 1950, and Dunn assumed Smith-Clarke's position as chief engineer, remaining in that position until 1959.
De Freville's first engine design was a four-cylinder engine with aluminium pistons and pressure lubrication, which was unusual for that time. The first car model using de Freville's engine was the Alvis 10/30. It was an instant success and established the reputation for quality workmanship and superior performance for which the company was to become famous. The original 10/30 side-valve engine was improved, becoming by 1923 the overhead valve Alvis 12/50, a highly successful sports car that was produced until 1932. Around 700 of the 12/50 models and 120 of the later Alvis 12/60 models survive today.
1927 saw the introduction of the six-cylinder Alvis 14.75 and this engine became the basis for the long line of luxurious six-cylinder Alvis cars produced up to the outbreak of the Second World War. These cars were elegant and full of technical innovations. Independent front suspension and the world's first all-synchromesh gearbox came in 1933 followed by servo assisted brakes. The Alvis 12/75 model was introduced in 1928, a model bristling with innovation, such as front-wheel drive, in-board brakes, overhead camshaft and, as an option, a Roots type supercharger.
In 1936 the company name was shortened to Alvis Ltd, and aircraft engine and armoured vehicle divisions were added to the company by the beginning of the Second World War. Smith-Clarke designed several models during the 1930s and 1940s, including the six-cylinder Speed 20, the Speed 25, and the Alvis 4.3 Litre mode
Car production was initially suspended in September 1939 following the outbreak of war in Europe, but was later resumed and production of the 12/70, Crested Eagle, Speed 25, and 4.3 Litre continued well into 1940.
Rover took a controlling interest in Alvis in 1965 and a Rover-designed mid-engined V8 coupé prototype named the P6BS was rumoured to be the new Alvis model. As part of Rover, Alvis Limited was incorporated into British Leyland but was bought by United Scientific Holdings plc in 1981.