he joined championship side crystal palace on loan until the end of the 2010–11 season on 24 march 2011. on the loan deal, mahon stated — "i'm very much pleased to have joined. it's been stop-start for me this season and i need to be playing in and amongst the first team. if i can give some input off the pitch as well as on it that will be great". however, he did not make any appearances during the loan spell and returned to his parent club in may 2011. a month after his return, it was announced that mahon was one of eight players to be released by qpr. during his time at the club, he scored four goals in 66 appearances.