Croydon South was a constituency represented in the House of Commons of the Parliament of the United Kingdom.

It elected one Member of Parliament (MP) by the first past the post system.

David Rees-Williams held the seat from the 1945 Labour landslide until unfavourable boundary changes in 1950.

Otherwise the seat, and indeed the rest of Croydon, had always been firm Conservative territory.

From 1950 until 1955 the seat was divided into east and west, represented by Conservatives Herbert Williams and Richard Thompson respectively.