The President will meet political leaders in both countries, as well as Maori elders in New Zealand
President Michael D Higgins will make state visits to Australia and New Zealand next month.
Áras an Uachtaráin confirmed that President Higgins has accepted the invitations of the two governments.
There are currently 80,000 Irish-born people living in Australia - as well as 2.5 million who have indicated they have Irish ancestry.
During his visit, the President will meet with the Irish communities in Perth, Melbourne, Hobart, Canberra, Sydney and Brisbane.
He will also meet with Prime Minister Malcolm Turnbull and Governor General Peter Cosgrove, as well as various state, business, cultural and academic figures.
The President's office says the visit "will be an opportunity to celebrate the significant contribution of the Irish Australian community to Australia's multicultural society".
Following his visit to Australia, President Higgins will continue to neighbouring New Zealand.
As well as meetings with officials including the country's Prime Minister - currently Bill English, who is contesting an election this coming weekend - the Irish President will also meet Maori elders.
He will also meet with business representatives, academics, artists, sports bodies and political leaders in Wellington, Christchurch and Auckland.
In a statement announcing the visit, Áras an Uachtaráin said: "The State Visit to a country with which Ireland has many shared interests is intended to strengthen political, cultural and economic ties between the two nations, as well as to reach out to members of the Irish diaspora living in New Zealand.
"There are an estimated 13,000 Irish citizens in New Zealand, and some 600,000 people in New Zealand have Irish ancestry. Irish culture, values and influence have been tangible throughout the modern history of New Zealand."