Holborn and St Pancras South was a parliamentary constituency centred on the Holborn district of Central London.

It returned one Member of Parliament (MP) to the House of Commons of the Parliament of the United Kingdom, elected by the first-past-the-post voting system.

The constituency was created for the 1950 general election, and abolished for the 1983 general election, when it was largely replaced by the new constituency of Holborn and St Pancras.

1950–1974: The Metropolitan Borough of Holborn, and wards five, six, seven and eight of the Metropolitan Borough of St Pancras.

1974–1983: The London Borough of Camden wards of Bloomsbury, Euston, Holborn, King's Cross, Regent's Park, and St Pancras.