Castlewood House in Dingle, meanwhile, has been named the third best bargain hotel in the world
A five-star hotel in Kerry has been named the best in Ireland.
The Killarney Park Hotel came in at number one in TripAdvisor's annual Travellers' Choice Awards for 2018, and was also rated as the 17th best hotel in the world.
For Ireland specifically, Harvey's Point in Lough Eske in Co Donegal came in second, with Ashford Castle in Co Mayo in third.
Castlewood House in Dingle, meanwhile, was voted the third best bargain hotel in the world, while Ballyfin, Co Laois comes seventh in the world's top 25 small hotels.
Reacting to the accolade, Niamh O'Shea - manager of the Killarney Park Hotel - said: "We're absolutely over the moon here at the Killarney Park. It was a huge surprise.
"It's well deserved for all the hard-working team here. It's a family-owned hotel. I suppose the ethos has always been 'warmth beyond a smile', so that's what we're about - giving good service, but in a nice, warm and friendly atmosphere."
She added: "Killarney Park is right bang in the middle of Killarney town. Killarney [also] has thousands of acres of national park, so our guests get to enjoy the best of both."
You can see the list of the ten best hotels in Ireland below, while the full rankings for Ireland and the world can be found on the TripAdvisor website: