Charnley has agreed a new deal which will see him stay at Wigan until 2016, while Mcllorum has penned a three-year contract, with the club holding an option for an additional season.
Furthermore, captain O’Loughlin has rejected a move to the NRL in favour of ending his career at the DW Stadium.
“To say I am pleased to have secured the services of these three players would be a massive understatement,” said Wigan head-coach Sean Wane.
“Josh, Lockers and Mickey are part of the back bone of this great club. Their attitude to training and improving as players is exceptional and they are perfect examples to any youngster wanting to get to the highest level of rugby league.
“Like me, these players have a great desire to make Wigan clearly the greatest club in the world again. I would personally like to thank Ian Lenagan for his support in making this happen.”
Elsewhere, there is a new one-year contract for Bradford forward James Donaldson who missed all but two games of the season through injury.
“It’s like starting all over again now,” he said. “I’ve done my knee twice but this is a clean slate.
“My body is feeling good and I can’t wait to get back in training and try and put things right again.
“There was a few other options but there was nowhere else I wanted to be because I love Bradford.”
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