Over 70 people have died with Covid-19 in the Navajo Nation, which lies across parts of Utah, Arizona and New Mexico.
Navajo and Hopi families set up a GoFundMe campaign to raise money for food, water, essential supplies and personal protective equipment, which has raised more than $1.6m (£1.3m).
Several donations came from Ireland, inspired by the help provided by the Choctaw Nation tribe during the Great Famine.
The native American tribe donated $170 — the equivalent of $5,000 today — to help the Irish people in 1847.
Around 60,000 native Americans, including the Choctaw, had suffered through the Trail of Tears, a series of forced relocations from their ancestral homelands during which thousands died from starvation, disease and exposure.
A message from one Irish donor, Pat Hayes, said: “From Ireland, 170 years later, the favour is returned!
“To our native American brothers and sisters in your moment of hardship.”
One of the campaign’s organisers, Vanessa Tulley, wrote: “The heartache is real.
“We have lost so many of our sacred Navajo elders and youth to Covid-19. It is truly devastating. And a dark time in history for our Nation.
“In moments like these, we are so grateful for the love and support we have received from all around the world. Acts of kindness from indigenous ancestors passed being reciprocated nearly 200 years later through blood memory and interconnectedness.
“Thank you, Ireland, for showing solidarity and being here for us.”