Cardiff Bus is the dominant operator of bus services in Cardiff, Wales and the surrounding area, including Barry and Penarth. The company is wholly owned by Cardiff Council and is one of the few municipal bus companies to remain in council ownership.

Bus transport in Cardiff, the capital and most populous city in Wales, forms the major part of the city's public transport network, which also includes an urban rail network, Waterbus and international airport. Cardiff is a major city of the United Kingdom and a centre of employment, retail, business, government, culture, media, sport and higher education.