A school bus is a type of bus owned, leased, contracted to, or operated by a school or school district and regularly used to transport students to and from school or school-related activities, but not including a charter bus or transit bus. Around the world, various configurations of buses are used; the most iconic examples are the yellow school buses seen in the United States and Canada.

In North America, school buses are purpose-built vehicles distinguished from other types of buses by design characteristics mandated by federal and state regulations. In addition to the use of a vehicle-specific paint color (school bus yellow), school buses are fitted with exterior warning lights (to give them traffic priority) and multiple safety devices.[2] Outside North America, purpose-built vehicles for student transport are less common. Depending on location, students ride to school on transit buses (on school-only routes), coaches, or a variety of other buses.

Every year in the United States and Canada, school buses provide an estimated 8 billion student trips from home and school. Each school day in 2015, nearly 484,000 school buses transported 26.9 million children to and from school and school-related activities; over half of the United States K–12 student population is transported by school bus.

In the second half of the 19th century, many rural areas of the United States and Canada were served by one-room schools. For those students who lived beyond practical walking distance from school, transportation was facilitated in the form of the kid hack; at the time, "hack" was a term referring to certain types of horse-drawn carriages.

One of the longest-running school bus manufacturers, Wayne Works (later Wayne Corporation), started producing its first school wagons in Indiana in the late 1880s.[6][7] Essentially a re-purposed farm wagon with the addition of interior bench seats, the design featured a rear entrance door. As kid hacks were horse-drawn vehicles, the feature was intended in order to avoid startling the horses while loading or unloading passengers.