Motor bus or motorbus is a now somewhat archaic term referring to a bus powered by an onboard internal combustion engine, as opposed to a horse-drawn bus, steam bus or trolleybus. Motor buses began appearing on public roads shortly before the turn of the 20th century, and by 1905 were a significant feature of, e.g. the streets of London. They are now commonly referred to simply as "buses".

"The Motor Bus" is a macaronic poem written in 1914 by Alfred Denis Godley (1856–1925).