The seat of Murdoch was established on 9 June 1976 in a redistribution under the Electoral Districts Act 1947, and was first contested at the 1977 state election. While initially thought to be reasonably safe for the Labor party, major demographic change in the mid-1970s resulting from the creation of suburbs such as Bull Creek and Leeming on what had previously been swampy agricultural land, resulted in a relatively safe Liberal seat by the time of the election, and Barry MacKinnon easily won the seat. MacKinnon went on to become Leader of the Opposition from 1986 until 1992, when he lost the leadership to Richard Court and subsequently retired from politics.