Age: 28 years, 2 months
Place of Birth: Mayo
Height: Not Available
John joined Mervue United for the 2011 season and made his league debut coming on as a 73rd minute substitute away to Athlone Town on 22nd April 2011. In all, he made 20 league appearances in his debut season, adding one goal as Johnny Glynn's side finished 7th in the First Division.
In January 2012, John signed for Sean McCaffrey at Dundalk and made 26 league appearances in his first year at Oriel Park. In 2013 he added a further 20 league appearances under new boss Stephen Kenny as the Lilywhites finished second in the league behind champions St Patrick's Ath.
2014 brought John's first league title winners medal. He scored two goals in 21 league appearances as Dundalk secured the Premier Division title on the last day of the season. He also played in three of their four Europa League games, scoring in the 3-1 home win over Jeunesse Esch. 2015 was even more successful with John playing in all 33 league games and scoring three times, as Dundalk once more won the Premier Division title. He also appeared in the FAI Cup Final, in which Dundalk beat Cork City 1-0 after extra-time. A third title followed in 2016, with John scoring twice in 30 league appearances and making another FAI Cup final appearance, this time getting a runners up medal as Dundalk lost to Cork City. He also played in ten of Dundalk's 12 European games as they reached the group stage of the Europa League. John re-signed with Dundalk for the 2018 season. In October 2018, John signed a new two year deal with the club. In December 2020, John decided to leave Dundalk having won five League of Ireland titles, three FAI Cups, and three League Cups at Oriel Park.
In January 2021, John signed for Pats.