Playwright Brian Friel and authors Peter Sheridan and Jennifer Johnston were also among the literary names attached to the letter, which was published in the Irish Times.
"
Wars have always been cloaked with noble ideals... but the actual motives for conflict have very often been far more sinister and predatory
"
Letter from 41 writers
They join other writers including Harold Pinter, Jeanette Winterson and Lucy Irvine who have already spoken out against military action.
"The world is poised on the brink of war. We hope that it is not too late to prevent this conflict and wish to add our voice to the many millions throughout the world who are calling for the momentum towards war to be halted," the letter said.
The signatories also included My Left Foot scriptwriter Shane Connaughton, dramatist and poet Brendan Kennelly and author Joe O'Connor, brother of singer Sinead.
"Ostensibly the reason for this war is to check the possibility of Saddam Hussein using weapons of mass destruction," the letter said.
"But is it not clear that the most immediate victims of his repressive government, his own citizens, are those who will suffer terribly in the event of war?"
Freedom
It questioned whether the world would be a safer place if a short conflict led to the replacement of Saddam Hussein.
"Wars have always been cloaked with noble ideals, such as the defence of 'small nations', 'democracy' 'freedom'. But the actual motives for conflict have very often been far more sinister and predatory," it said.
"In this case it suffices to draw attention to the fact that Iraq controls the world's second largest oil reserve."
"We oppose a US led war against Iraq."
Meanwhile, in the UK, leading figures at the National Theatre in London are planning to mount their own anti-war protest.
Actors Ralph and Joseph Fiennes, Corin Redgrave, Janet McTeer, Catherine McCormack, Lorcan Cranitch and Eileen Atkins will appear for the press with an anti-war banner on Monday.
They will be joined outside the venue by board members Joan Bakewell, Sue McGregor and Zoe Wanamaker, as well as outgoing director Trevor Nunn and his replacement, Nicholas Hytner.