St Marylebone (UK Parliament constituency)

1918–1950: The Metropolitan Borough of St Marylebone wards of Bryanston Square, Cavendish, Church Street, Dorset Square and Regent's Park, Hamilton Terrace, Langham, Park Crescent, Portman, and St John's Wood Terrace.

1950–1974: The Metropolitan Borough of St Marylebone wards of Bell Street, Bryanston Square, Cavendish Square, Church Street, Dorset Square, Hamilton Terrace, Lord's, Park Crescent, Portman Square, and St John's Wood Terrace.

1974–1983: The City of Westminster wards of Baker Street, Cavendish, Church Street, Lord's, and Regent's Park.

As shown by the maps, inset, there was no change in substance to the outer ward boundaries of this constituency during its lifetime.

The political parties had been making preparations for an election to take place and by the Autumn of 1939, the following candidates had been selected;