The Hillman Imp was a compact, rear-engined sedan automobile manufactured by the Rootes Group from 1963 to 1976.

Known internally within Rootes as the "Apex", the Imp was intended as a rival to the Mini. The key difference between the two cars was the Imp's 875 cc all-aluminium ex-Coventry Climax fire pump engine which was mounted behind the rear wheels. In order to counteract the oversteer handling characteristics of a rear engined design, the Imp had a sophisticated front suspension. Through the use of an opening rear window, the car was effectively a hatchback. In true Rootes tradition, there was also some badge-engineered derivatives, such as the Hillman Husky, the pseudo-luxury Singer Chamois, and the sharp handling Sunbeam Sport (with a more powerful 1.0 litre engine).

The Imp was a massive and expensive leap of faith for Rootes. Not only did it not have any real experience in building small cars or indeed wholly aluminium engines, it was forced to build a new assembly plant on the outskirts of Glasgow, in the town of Linwood in which to assemble the Imp, since planning regulations banned it from further expanding its Ryton plant near Coventry. The investment also included an advanced die-casting plant to manufacture the aluminium engine casings, and a stake in the Pressed Steel company which manufactured body panels. The problem was that Linwood was over 300 miles away from Ryton, and the engine castings although made in Linwood, would have to be sent to Ryton to be machined and assembled, and then sent back up to be put on the cars - a 600 mile round trip.

The Glaswegian workforce who were all recruited from the shipbuilding industry were also not versed in the intricacies of motor vehicle assembly, and Imp build quality and reliabilty suffered. They also brought with them their militant left-wing values, and as a result strike action and industrial disputes were a rule rather than an exception. The daring design of the Imp was also somewhat underdeveloped, and engine, mechanical problems and electrical fires were commonplace. However the car itself was relatively popular, thanks to its competitive price, distinctive styling and cheap running costs.

The huge investment in both the Imp and the Linwood production plant proved to be the undoing of Rootes, and its commercial failure led to huge losses to the Coventry-based firm. By 1967 the company had fallen into the hands of Chrysler, whose stewardship led to the death of the Imp in 1976, after fewer than 500,000 Imps were built and the entire Rootes empire collapsed two years later, when it became part of Peugeot.

The Ryton assembly plant survives to this day, which now manufactures various Peugeot models, but the Linwood plant was closed in 1981.