BBC One is a British free-to-air public broadcast television channel owned and operated by the BBC. It is the corporation's flagship channel and is known for broadcasting mainstream programming, which includes BBC News television bulletins, primetime drama and entertainment, and live BBC Sport events.

BBC One was launched on 2 November 1936 under the name BBC Television Service, which was the world's first regular television service with a high level of image resolution. It was renamed BBC TV in 1960 and used this name until the launch of the second BBC channel, BBC2, in 1964. The main channel then became known as BBC1. The channel adopted the current spelling of BBC One in 1997.

The channel's annual budget for 2012–2013 was £1.14 billion. It is funded by the television licence fee together with the BBC's other domestic television stations and shows uninterrupted programming without commercial advertising. The television channel had the highest reach share of any broadcaster in the United Kingdom as at 2019, ahead of its traditional rival for ratings leadership ITV. In 2013, a major global study of the BBC by the Populus polling organisation found BBC One to be rated the highest-quality TV channel in the world, with BBC Two coming in third place.