Career
Early He previously played with hometown club Monaghan United, Glenmuir (Dundalk) and Drogheda Boys at underage level University College Dublin McMahon was awarded a soccer scholarship at University College Dublin in 2008, he officially joined University College Dublin for their 2009 League of Ireland First Division campaign under Martin Russell. Drogheda United Mid-way through the 2010 Premier Division campaign McMahon departed University College Dublin to return for former club Drogheda United.
He made a total of 37 competitive appearances for University College Dublin, scoring 3 goals.
McMahon took a short break out of the game at the start of the 2011 season to concentrate on his final year at college in University College Dublin. Mid-way through the 2011 season, Mick Cooke re-signed McMahon for Drogheda United. Bohemians In January 2012, Peter moved to Dalymount Park and Bohemians under Aaron Callaghan.
Portadown In February 2013, Peter moved closer to his hometown of Monaghan to Shamrock Park and Portadown under Ronnie McFall. McMahon agreed a 2-year deal with Portadown at the end of his first season with the club on May 1st 2014.
Club University College Dublin League of Ireland First Division (1): 2009 League of Ireland Under 20 (1): 2009 Collingwood Cup (2): 2009, 2010 CUFL Cup - Premier Division (1): 2010 Individual Portadown: 2013.
