South Hertfordshire was a constituency in Hertfordshire which returned one Member of Parliament (MP) to the House of Commons of the Parliament of the United Kingdom. It was created for the February 1974 general election and abolished for the 1983 general election when it was mainly replaced by the new Hertsmere constituency.

Statutory definition

• The Urban District of Potters Bar;
• the Rural District of Elstree;
• in the Rural District of St Albans the parishes of Colney Heath, London Colney, and St Stephen; and
• in the Rural District of Watford the parish of Aldenham.^[2]

Components' immediate predecessor seats

• The land of the Urban District of Potters Bar in local government administration-abolished Middlesex has been in Hertfordshire since the creation of Greater London in 1965. It now moved into this new seat from the abolished Enfield West seat. 

• The Rural District of Elstree was in the abolished Barnet seat. 

• The three St Albans district parishes came from the very long-lived St Albans seat and Aldenham came from South West Hertfordshire.

Components' immediate successors

• Colney Heath went back to the St Albans seat and St Stephen transferred to the Watford seat. 

• The rest formed most of the new constituency of Hertsmere.