公共汽车是一种以中型或大型汽车（大客车/巴士）作为运送手段，以运输大量乘客的的大众运输服务。

公共汽车在中文地区中的名称不尽相同。

A transit bus (also commuter bus, city bus, stage bus, public bus or simply bus) is a type of bus used on shorter-distance public transport bus services which include low-floor buses, double-decker buses, articulated buses and midibuses.

These are distinct from all-seated coaches used for longer distance journeys and smaller minibuses, which are typically used for paratransit (demand-responsive) services.