O'Neill was in attendance at Tallaght Stadium when Stephen Kenny's team overcame BATE Borisov in the UEFA Champions League Third Qualifying Round and relayed to the players afterwards how impressed he was with their performance.
Now, Dundalk take on Legia Warsaw in the Aviva Stadium on Wednesday, August 17 and O'Neill has sent a message of support to The Lilywhites as they bid to become the first Irish club to reach the UEFA Champions League Group Stages.
"When the final whistle blew in Tallaght less than a fortnight ago it signalled the start of glorious celebration. Dundalk had defied great odds to knock out BATE Borisov, serial qualifiers for the UEFA Champions League Group Stages. And in so doing, they played magnificently, scoring three brilliant goals to complete an unforgettable evening," said O'Neill.
"It was an absolute privilege to witness such a performance. Everything needed to go through was on show - desire, passion, drive, great passages of play, and patience. All of these qualities will again be needed against Legia Warsaw.
"But Stephen Kenny has instilled a very strong self belief in the team, clearly evident in the trophies won in recent seasons. From a distance it seems they possess outstanding characters in the squad, a great team spirit and a strong mentality.
"Dundalk have already given the SSE Airtricity League an enormous boost. Qualification for the Group Stage of the Champions League would be absolutely incredible. The atmosphere in Tallaght was electric and the supporters played a very important part that evening. I'm sure the same will apply at the Aviva Stadium.
"Final hurdles, by nature, are difficult to overcome, but if the performance in Tallaght is any type of barometer, they will still be there fighting at the end. I wish Stephen, his team and his club, the best of luck."
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