Northamptonshire South (UK Parliament constituency)

South Northamptonshire
County constituency for the House of Commons
Boundary of South Northamptonshire in Northamptonshire for the 2010 general election.
Location of Northamptonshire within England.
County	Northamptonshire
Electorate	82,956 (December 2010)
Major settlements	Brackley, Towcester
Current constituency
Created	2010
Member of parliament	Andrea Leadsom (Conservative)
Number of members	One
Created from	Daventry
1950–1974
Number of members	One
Replaced by	Daventry
Created from	Daventry
1832–1918
Number of members	1832–1885: Two 1885–1918: One
Replaced by	Daventry
Overlaps
European Parliament constituency	East Midlands

South Northamptonshire is a constituency represented in the House of Commons of the UK Parliament since its 2010 recreation by Andrea Leadsom, a Conservative who has been Secretary of State for Environment, Food and Rural Affairs since 14 July 2016.

Before 2010, the constituency existed from 1832–1918, and from 1950-1974, however on different boundaries during each period. It elected two Members of Parliament (MPs) by the bloc vote system of election from 1832, until the representation was reduced in 1885 to one member elected by the first past the post system.

Three names feature prominently among the area's Commons members, the 3rd and 5th Earl Spencer (during their tenures as MP having a courtesy title only, Viscount Althorp - Althorp is a major country house in the seat, well known as the childhood home of Princess Diana of Wales); Edward Fitzroy (son of Lord Southampton), Speaker of the House of Commons from 1928 until his death in 1943; and lastly, Reginald Manningham-Buller, 1st Viscount Dilhorne who on accomplishment of a peerage sat for the final two years of his life as the historic equivalent of the President of the Supreme Court of the United Kingdom with additional functions, the Lord Chancellor.