The Hollywood top gun is set to be presented with a Certificate of Irish Ancestry at the Department of Foreign Affairs on Wednesday.
Cruise, who was born Tom Cruise Mapother IV, has ancestry on his father's side in Kilteevan, Co Roscommon, and Co Dublin through both the Mapother and Cruise families.
The Gathering has commissioned geneological research which will demonstrate the connection definitively.
There has been a lot of speculation in the past about the Mission Impossible star's Irish roots, which are in Roscommon and Co Dublin, but new research will be unveiled which will show a more recent connection to Ireland than before.
The Mapother family were originally from Dorset, but have been in Ireland since Elizabethan times.
Cruise's great-great grandmother was the last Mapother ancestor to live in Ireland. She emigrated to the United States in the middle part of the 19th century.
The actor's visit to Ireland will be hosted by Universal Pictures International Ireland.
David Burke, its general manager, said they were delighted to welcome him to Irish shores for the premiere of his new film Oblivion.
"We are thrilled Tom is returning to Ireland to launch his latest movie, Oblivion. It's a huge bonus we can share this new information with Tom about his Dublin heritage."