[1] The division was named after Charles Yelverton O'Connor, the Engineer-in-Chief of Western Australia most famously known for designing the Fremantle Harbour and the Goldfields Pipeline.

For its first three decades, it took in large portions of the Mid West, Wheatbelt and Great Southern regions of Western Australia with major population centres in Geraldton and Albany.

The other large country seat in Western Australia, Kalgoorlie, already the largest single-member electorate in the world, needed to expand in size.

[2] It now includes the Great Southern region (Albany, Broomehill-Tambellup, Cranbrook, Denmark, Gnowangerup, Jerramungup, Katanning, Kent, Kojonup, Plantagenet, and Woodanilling), the Goldfields-Esperance region (Coolgardie, Dundas, Esperance, Kalgoorlie-Boulder, Laverton, Leonora, Menzies, Ngaanyatjarraku, and Ravensthorpe), the Mid West Shire of Wiluna, parts of the South-West region (Boyup Brook, Bridgetown-Greenbushes, Collie, Manjimup and Nannup), and the southern portion of the Wheatbelt (Beverley, Boddington, Brookton, Bruce Rock, Corrigin, Cuballing, Cunderdin, Dumbleyung, Kellerberrin, Kondinin, Koorda, Kulin, Lake Grace, Merredin, Mount Marshall, Mukinbudin, Narembeen, Narrogin, Nungarin, Pingelly, Quairading, Tammin, Trayning, Wagin, Wandering, West Arthur, Westonia, Wickepin, Williams, Wiluna, Wyalkatchem and Yilgarn).

However, severe conflict between rival branches of the state National Party allowed Liberal Wilson Tuckey to take the seat on Labor preferences.