A car rental or car hire agency is a company that rents automobiles for short periods of time (generally ranging from a few hours to a few weeks) for a fee. It is an elaborate form of a rental shop, often organized with numerous local branches (which allow a user to return a vehicle to a different location), and primarily located near airports or busy city areas and often complemented by a website allowing online reservations.

Car rental agencies primarily serve people who have a car that is temporarily out of reach or out of service, for example travellers who are out of town or owners of damaged or destroyed vehicles who are awaiting repair or insurance compensation. Because of the variety of sizes of their vehicles, car rental agencies may also serve the self-moving industry needs, by renting vans or trucks, and in certain markets other types of vehicles such as motorcycles or scooters may also be offered.

Alongside the basic rental of a vehicle, car rental agencies typically also offer extra products such as insurance, global positioning system (GPS) navigation systems, entertainment systems, and even such things as mobile phones.