Relationships Australia had its genesis in the years following World War II, with many marriages succumbing to the stress of long, traumatic separations and difficulties when servicemen returned from active duty. At the time it became clear there was a need to support families and assist couples to re-develop close communication and mutual support and, where possible, renewed commitment to their marriages.
Australian political and religious leaders looked overseas for ideas on how to support marriages and families. They identified a model in the United Kingdom, in which the newly established National Marriage Guidance Council had 400 voluntary trained counsellors working in 80 branches across the country.

The establishment of Marriage Guidance Councils in Australia can be attributed to two pioneers - the Reverend W G Coughlan and the Reverend E P Blamires. In his historical notes of the first decade of the Marriage Guidance Council's work, Reverend Blamires spoke of the urgent need for Australian church and state leaders to respond to the steep rise in divorce and marital disharmony that arose from life in the post-war period of 1946. In 1948, Reverend Coughlan wrote to the London office of the National Marriage Guidance Council stating:

I believe we shall be able, if you stand by us and support our plans, to get in time half-a-dozen solid Councils, each with a centre and all of them working to substantially the same constitution and aligned to each other by bonds of common outlook and ambition ... we aim at a national setup.

The first national conference of Australian Marriage Guidance Councils was held in Melbourne in 1952, and in 1953, the National Marriage Guidance Council of Australia was formed. The purpose for forming the national body was:

To enable each participating council to pursue its work with greater effectiveness. To inaugurate, if possible, a national organisation for interstate collaboration and united approach to governments and other bodies.

The first government funding to the National Marriage Guidance Council of Australia was granted in 1956.

From the start, there was a focus on the establishment of professional standards for counsellors as well as providing training and accreditation. The National Marriage Guidance Council of Australia promoted collaboration across the developing marriage guidance sector. Following a tour of National Marriage Guidance Council centres across the country in 1968, the National Secretary noted a recognisable common quality of spirit and skill that distinguishes our practitioners as having been trained within the Marriage Guidance Council framework.

In 1994, the name of the organisation was changed to Relationships Australia Incorporated, to reflect a social shift in the understanding of families and relationships.

The current Relationships Australia federation has member organisations in each state and territory. There are more than 100 centres from which services are provided by 2,000 staff across the country. The organisation is secular and inclusive. Services are provided to all people and include programs for families, couples, children, individuals, workplaces and communities. The needs of same-sex couples and individuals, people from Aboriginal and Torres Strait Island backgrounds, people from culturally and linguistically diverse backgrounds, humanitarian entrants, and a large range of people with special needs are also key parts of our business.