车辆号牌是两面分别悬挂在车子前后的板材，通常使用的材质是铝、塑料或贴纸，在板上会显示有关车子的登记号码、登记地区或其他的基本数据，形状以美国、日本的长方形或是欧洲、中国大陆使用的长条形为主。车辆号牌也被称为车辆牌照或车牌。

号牌上的登记号码由指定的政府单位负责发配，执法相关单位（如警察、海关人员等）可以通过这个号码追踪到有关车辆的拥有者、登记年份、登记地区、罚单纪录和其他的相关数据，伪造登记号码或删改有关数据是属于犯罪的行为。

A vehicle registration plate is a metal or plastic plate attached to a motor vehicle or trailer for official identification purposes. These vehicles with these purposes include cars, trucks, vans, buses, motorcycles, bikes, bicycles, trikes, tricycles, scooters, possibly hoverboards and segways, tractors, and golf carts, but not unicycles. The registration identifier is a numeric or alphanumeric code that uniquely identifies the vehicle owner within the issuing region's database. In some countries, the identifier is unique within the entire country, while in others it is unique within a state or province. Whether the identifier is associated with a vehicle or a person also varies by issuing agency. Depending on the country, the vehicle registration plate may be called a license plate (United States, Canada), or number plate (India, United Kingdom, Australia).