Republicans tried to "politicise" sport by holding a hunger strike 25th anniversary commemoration at a GAA stadium, the DUP has said.
The rally commemorated the hunger strikes at the Maze prison
Hundreds of republican supporters and former prisoners gathered at a rally in Casement Park in Belfast on Sunday.
The GAA's Central Council in Dublin had said the rally would break its rules about staging political events.
However, it is understood the GAA's Antrim County Board, which looks after Casement Park, raised no objections.
DUP assembly member Diane Dodds said the hunger strikers "were guilty of some of the vilest crimes against innocent people in this province".
"One can just imagine the outcry if a unionist party were to stage a rally celebrating the activities of a terrorist loyalist organisation," she said.
Editorials in both the unionist News Letter and nationalist Irish News condemned the location of the rally at Casement Park.
The Irish News said "while the opposition to the rally at central council level needs to be highlighted", there "could be little doubt" the GAA was left "in an uneviable position".
"In future, Casement Park must be kept exclusively for sporting purposes," the paper said.
The News Letter said it was a "most blatant abuse of an arena that has, we are told, specific uses for sporting activities".
"Questions must be answered by the GAA authorities about what the precise raison d'etre of the organisation is," the editorial added.
Thousands of people lined the streets of west Belfast for a parade ahead of the rally, commemorating the deaths of 10 IRA and INLA inmates in the 1981 protest over political status at the Maze prison in County Antrim.
Gerry Adams told the rally that Sinn Fein supporters needed to take courage from the actions of the hunger strikers.
"We need, and this is essential, confidence in ourselves and in our position," he said.
"The hunger strikers knew exactly what they were doing, why they were doing it, and the effect that actions would have.
"We also, friends, know exactly what we are doing, why we are doing it and the effect our actions will have and that is how are we are going to continue to build this struggle."