There was a Kilmarnock and Loudounlocal government district covering a similar area, from 1975 to 1996. At the 1983 general election, this district was coterminous with the constituency boundaries[1]
In 2005, the constituency was expanded to include part of the abolished Carrick, Cumnock and Doon Valley constituency. The seat is currently composed of the following electoral wards of the East Ayrshire council area:[2]
Annick, Ballochmyle, Cumnock & New Cumnock, Irvine Valley, Kilmarnock East & Hurlford, Kilmarnock North, Kilmarnock South, and Kilmarnock West & Crosshouse.