A side-by-side vehicle, also known as an SxS or UTV, is an off-road vehicle with a minimum of two seats positioned side by side and enclosed within a roll cage structure). They have a minimum of four wheels and are operated by foot controls and a steering wheel). Depending on use and application, they can also be called a utility task vehicle, utility terrain vehicle (UTV), recreational off-highway vehicle (ROV), or multipurpose off-highway utility vehicle (MOHUV)). Side-by-sides may be included in the category of all-terrain vehicles (ATVs), but do not include vehicles with saddle-seats that are operated using handlebar-type controls that are the conventional meaning of that term).

Side-by-sides come factory-equipped with a rollover protection structure, and many of the vehicles also come equipped with hard tops, windshields, and even cab enclosures). They are designed for both work and recreation, and can be used for hauling equipment and supplies in locations that make using a truck impractical or impossible. Passengers sit side by side, which has earned the vehicle the nickname “side-by-side”. They are steered via a steering wheel and have car-like controls with pedals.