Regent Street is a major shopping street and thoroughfare in London's West End. Named after the Prince Regent (later George IV), it was built by John Nash as part of a ceremonial route from the Regent's residence at Carlton House in St James's to Regent's Park. Starting as Lower Regent Street at its intersection with Charles II Street and Waterloo Place, it runs north to Piccadilly Circus then becomes Regent Street by turning westward, and curves around in a quarter-circle until it is heading north once more. It then continues past Oxford Circus becoming Upper Regent Street and ends at its intersection with Langham Place, Cavendish Place and Mortimer Street.

There is a yearly Regent Street Festival, and the Christmas light displays are a London tradition, with a "celebrity" being chosen annually to ceremonially light them up. In recent years, the Christmas lights have been used predominantly as just another advertising venue, usually for films aimed at a younger audience. As well as shops, there is a large amount of office accommodation on the upper floors of the buildings. The street features as one of the locations on the standard London version of the Monopoly board game.

Oxford Circus is the junction where Regent Street crosses Oxford Street, and the site of one of the busiest of London's underground stations. The Central, Bakerloo and Victoria lines all meet here.