Boyzone "gave a day to Omagh" on Saturday, holding two concerts and meeting people injured in the August explosion.
Lead singer Ronan Keating said the two concerts were the most "special" they had performed.
The money raised from ticket sales - expected to top £20,000 sterling - is going to the Omagh fund for the victims of the bomb and their families.
Ronan Keating said: "To be greeted like this here is wonderful. We're just glad to be here to do what we can to help. The response when we went out on stage was phenomenal."
He said the band was on tour in Europe when they heard of the bombing and they had wanted to do something to help as soon as they could. "We couldn't believe it. It was devastating," said singer Keith Duffy. "But we were so busy at the time we didn't get a chance to send our love."
After the matinee performance, the Boyzone members met 150 young people injured by the bomb. They announced that they were donating to the Omagh fund their platinum disc, which the group received for the sales of Whatever You Do.
Ms Pauline Greene (19), from Omagh, who had her ankle blown off and was severely burned in the explosion, said afterwards that seeing Boyzone was a terrific boost. Ms Greene, who spent four months in hospital, is taking a year out from her studies to recover. She plans to become an art teacher.
She said meeting and talking with the Boyzone members was like a dream come true. She was amazed at "how genuine and down to earth the lads were" and that they seemed to really care about the people of Omagh.
Group member Mikey said the Omagh concerts had been very important. "I have never felt as proud in all my career with the band as I did today, playing for the people of Omagh."
The event was welcomed as a major boost for the town and the young people were clearly delighted. "It was excellent", said Ms Una McGurk (14), who was injured in the blast.
"It was great for them to come all this way to do a concert for us. It's been the talk of the town for ages, everyone's been looking forward to it since Christmas. It's a great start to the New Year. Let's hope 1999 is a better year than 1998."