Killarney National Park in Co Kerry is to be paired with Glacier National Park in the US state of Montana.
The agreement signed between Ireland and the United States will make the two sites "sister parks" and will allow for the exchange of ideas about how best to manage the amenities.
There will be collaboration on a variety of shared challenges such as high visitor numbers, controlling exotic and invasive species, working with local communities, and ecological monitoring.
Cathaoirleach of the Seanad, Fianna Fáil Senator Mark Daly, worked with the US Department of the Interior on the project.
"This agreement between Ireland and the United States affirms once again the strong links and enduring friendship between our two republics," he said.
Minister for Housing, Local Government and Heritage Darragh O'Brien is the signatory on the agreement on behalf of Killarney National Park.
"I am delighted that my Department, through the National Parks and Wildlife Service, is entering into a Sister Park arrangement with the US National Park Service by developing best practices and establishing closer links between Killarney National Park and Glacier National Park, Montana," Mr O'Brien said.