Milton Keynes South West was a constituency represented in the House of Commons of the Parliament of the United Kingdom from 1992 to 2010.

As its population grew, Milton Keynes then gained its own constituency, which was taken by William Benyon of the Conservative Party.

The new South West constituency was taken by Barry Legg of the Conservatives, who lost the seat to Labour's Phyllis Starkey in the 1997 election.

Phyllis Starkey ran in the Milton Keynes South seat, but lost to the Conservative candidate Iain Stewart.

The constituency consisted of 12 electoral wards of the Borough of Milton Keynes: Church Green, Denbigh, Eaton, Fenny Stratford, Loughton, Manor Farm, Newton, Stony Stratford, Whaddon, Wolverton, Wolverton Stacey Bushes, and Woughton.