Opus Dei, the Catholic Church's first personal prelature, has attracted a great deal of passion and argument in its 60 or 70 years of existence. Very little has been written about Opus Dei in this part of the world, and as far as I am aware, no previous academic research has been done. The purpose of this thesis is to give the reader a brief overview of Opus Dei and its beginnings in this part of the world. I have begun by looking at the development of the pioneer Georgian and Victorian world where Australasian Catholicism has its roots, at the people who made up that world, and their customs and beliefs. The success or failure of the Opus Dei enterprise in this part of the world is obviously very much bound up with the kind of people and religious attitudes they encountered on arrival. A variety of new Catholic groups sprang up during the twentieth century. A number, like Opus Dei, had their origins in traditional European Catholicism, but soon spread further afield. Other groups remained more exclusive. A comparison shows that while Opus Dei's structure and status in canon law is at present a unique one, other groups are similarily organised in many respects Is Opus Dei a sect or cult within the Catholic Church, as some allege? A brief discussion on sects and cults follows, and concludes that though Opus Dei does exhibit a number of the typically identifying signs of such groups, it does not belong in either category. The world scene and the local Church situation of the time are considered in the following chapters as Opus Dei arrives in Oceania and settles into first Australian and then New Zealand life. It will be seen that the prelature is often at odds with what is happening in both the national Catholic churches and the wider community. My conclusion finds that there is much good in Opus Dei for the Church to affirm, but members' energies are probably too narrowly focused. A meeting of minds within the wider Church would be beneficial to all. Appendices enlarge on information given in the text, and list further sources of information for those who would like to investigate further.