Thomas Mckenna, 62, a former treasurer of Crossmaglen Rangers GAA had been due to go on trial facing 150 charges including a number of rape and serious sexual assault and scores of indecent assault offences.
These included several involved offences against children. The abuse is set to have taken place from December 1989 until August of 2018.
McKenna was rearraigned at Belfast Crown Court today for his charges He pleaded guilty to all charges.
The judge claimed he would be "punished severely" for his crimes against the "vulnerable young men".
Judge Patricia Smyth explained to McKenna. "By your pleas of guilty you have admitted a catalogue of terrible offences against vulnerable young men
“You will be punished severely for that.
She also addressed some of McKenna's victims who were watching via video link
Former Crossmaglen Rangers GAA club treasurer Thomas McKenna pleads guilty to 139 serious sexual offences https://t.co/Vg3nJdW6jC
— BBC News NI (@BBCNewsNI) September 29, 2022
"I praise your courage in coming forward to disclose these terrible crimes in very, very difficult circumstances.
"Today each of you is completely vindicated in the complaints you made against this man, and I hope that vindication will bring you some peace of mind to those of you who still suffer grievously," she told the victims
"Each of you has done a great public service in coming forward and I want to thank you for that."
In June 2021 McKenna had pleaded guilty to 23 charges but denied 150 others.
Those he admitted to included 18 counts of voyeurism, four of indecent assault of a male and one of making an indecent picture of a child.
Earlier court appearances heard allegations that McKenna had taken pictures and videos of his victims without their permission.
At one point the police told a hearing they had recovered 43,000 images and 8,000 short video clips from several devices they had seized.
McKenna, who has been on remand since his first arrest, was taken back into custody.
Sentencing is due to be reviewed in early November.