Kilmarnock and Loudoun is a county constituency of the House of Commons of the Parliament of the United Kingdom. It elects one Member of Parliament (MP), using the first-past-the-post voting system.

The constituency consists of the northern half of East Ayrshire and contains the town of Kilmarnock and the Irvine Valley.

In 2005, the constituency was expanded to include part of the disbanded Carrick, Cumnock and Doon Valley constituency.

There was a Kilmarnock and Loudoun local government district covering a similar area, from 1975 to 1996. At the 1983 general election, this district was coterminous with the constituency boundaries^[1]

It does not share the same borders as the Scottish Parliament constituency of the same name.

The main towns are:

• Newmilns and Greenholm
• Catrine *
• Auchinleck *
• Darvel
• Galston
• Hurlford
• Kilmarnock
• Kilmaurs
• Logan *
• Lugar *
• Mauchline *
• Muirkirk *
• Ochiltree*
• Sorn *
• Stewarton
• Dunlop

Those towns marked * were not part of the original Kilmarnock and Loudoun, but were absorbed from the disbanded Carrick, Cumnock and Doon Valley.

• List of UK Parliamentary constituencies in Scotland
• Kilmarnock and Loudoun district