An original copy of the 1916 Proclamation, which is one of only 50, is up for grabs for €150,000.
The copy was taken from the window of Mark's jewellers on Henry Street a day after the Easter Rising started in 1916, by an eyewitness.
The Proclamation of the Republic, also known as the 1916 Proclamation or the Easter Proclamation, was a document issued by the Irish Volunteers and the Irish Citizen Army during the Easter Rising, which began on April 24, 1916.
It is due to go under the hammer in one of the most important auctions in recent years on July 25 and 26 at Whyte's auctioneers.
The auction house's managing director, Ian Whyte, confirmed the copy is "in good condition".
"There are a few small holes in it but that is to be expected. There were only ever 50 copies made, with half of these in institutions, so it is very rare that one comes up for sale - hence the high prices," he said.
"The eyewitness took the copy from the jeweller's window, signed it and sold it on to a man in Liffey Street."
Up to 691 lots will go under the hammer, including a wealth of historically important material such as The Wolfe Tone Archive, The Thomas Ashe Archive, 1798 and 1916 Proclamations, 1916 Rising medals, uniforms and weapons, along with contemporary memorabilia.
There is a signed leather briefcase once owned by former British prime minister Tony Blair which he used during the Good Friday Agreement negotiations. Lot 347 is estimated at between €800 to €1,200.
It was subsequently once owned by singer/songwriter Chris de Burgh.
The briefcase, offered on behalf of an armed forces charity, is signed 'Best wishes, Tony Blair' on the side.