Cumnock West was one of 32 electoral wards of East Ayrshire Council.
Created in 1999, the ward elected one councillor using the first-past-the-post voting electoral system.
The ward was a Labour stronghold as the party successfully held the seat at every election.
In 2007, the ward was abolished and replaced by the multi-member Cumnock and New Cumnock ward as council elections moved to a proportional voting system – the single transferable vote – following the implementation of the Local Governance (Scotland) Act 2004.
The ward took in the western part of Cumnock including the neighbourhood of Holmhead.