Ireland's leader called it an "historic day" for Palestinians as his country, along with Norway and Spain, announced it would recognize the state of Palestine.
"Each of us will now undertake whatever national steps are necessary to give effect to that decision," prime minister Simon Harris said in Dublin.
Harris said he was "confident" other countries would join the initiative.
"This is an historic and important day for Ireland and Palestine," he said.
"On January 21 1919, Ireland asked the world to recognize our rights to be an independent state. Our message to the free nations of the world was a plea for international recognition of our independence, emphasizing our distinct national identity, our historical struggle, and our rights to self-determination and justice," he said in an address to the nation.
"Today, we use the same language to support the recognition of Palestine as a state."
He said Dublin's move would advance the prospect of a "permanent peace" in the region.
The decision by the three countries to recognize Palestine will take effect on May 28.
