Milton Keynes South is a constituency^{[lower-alpha 1]} represented in the House of Commons of the UK Parliament since its 2010 creation by Iain Stewart, a Conservative.^{[lower-alpha 2]}

In its 2023 Periodic Review of Westminster constituencies, the Boundary Commission proposes to abolish this constituency.^[3]

This constituency (and its counterpart, Milton Keynes North), came into being when the two Milton Keynes constituencies (Milton Keynes North East and Milton Keynes South West) were reconfigured following the Boundary Commission's Fifth Periodic Review of Westminster constituencies with the aim of equalising the electorate as between the constituencies in the light of population growth that had occurred mainly in the Milton Keynes Urban Area. This constituency is the more urban of the two.

Iain Stewart MP won the new constituency for the Conservatives in the 2010 general election. This new constituency is a very large part of the former Milton Keynes South West, which had been held by Phyllis Starkey for Labour for 13 years until the 2010 general election.

In the 2015 general election, Iain Stewart again won the Milton Keynes South constituency for the Conservative Party.

The constituency takes up the smaller part but more dense part of the City of Milton Keynes and is one of the borough's two constituencies. Milton Keynes South is primarily an urban area with some rural elements; the other, Milton Keynes North, covers a larger area and is more rural.^[4]

At its creation the constituency comprised the electoral wards of Bletchley and Fenny Stratford, Danesborough, Denbigh, Eaton Manor, Emerson Valley, Furzton, Loughton Park, Stony Stratford, Walton Park, Whaddon and Woughton.^[5]

Following a revision to the ward boundaries in 2013, the seat comprises part or all of the following Council electoral wards:^[6]

• Bletchley East
• Bletchley Park
• Bletchley West
• Bradwell (part)
• Broughton (part)
• Campbell Park & Old Woughton (part)
• Danesborough & Walton
• Loughton & Shenley
• Monkston (part)
• Shenley Brook End
• Stony Stratford
• Tattenhoe
• Woughton & Fishermead (part)

The City Council ward boundaries do not necessarily coincide with the town and parish council areas. Each ward returns three councillors so their electorates are broadly equal.

Further to the completion of the 2023 Periodic Review of Westminster constituencies, the seat will be abolished for the next general election, with its contents distributed three ways:^[3]

• Southern areas, comprising the three Bletchley wards together with Tattenhoe, to be combined with parts of the (to be abolished) constituency of Buckingham - including the town of Buckingham - to form the newly created constituency of Buckingham and Bletchley
• Stony Stratford to the reconfigured Milton Keynes North seat
• Remaining parts to be incorporated into the new constituency of Milton Keynes Central

• Milton Keynes North
• List of parliamentary constituencies in Buckinghamshire