Amateur US clubs Campion played with amateur
USL Premier Development League sides
Baton Rouge Capitals and
Ventura County Fusion while in college. While with Baton Rouge, he appeared in 15 games and scored 10 goals with 3 assists. Campion was named to the PDL's Southern Conference Team of the Year in the
2011 season. He stayed two seasons with Ventura County, but only appeared in one game without recording any points.
Norrby IF Campion signed with Swedish
Division 1 side
Norrby IF in 2013 after leaving UC Santa Barbara and made his debut on 21 April 2014, scoring in extra time. Despite being under
contract at Norrby IF, Campion went on a number of trials in Summer 2014 with
Sheffield Wednesday,
Yeovil Town,
Ipswich Town, and
Bradford City.
Port Vale He was signed on
loan by
Port Vale on a deal until 1 January 2015. A thigh injury caused a delay in his debut for the club, but made his first appearance with the Port Vale Reserves on 15 October 2014 in a 5–1 win over Wigan Reserves with Campion scoring twice. He made his debut in the
Football League on 29 November, coming on for
Ben Williamson 81 minutes into a 2–2 draw at
Gillingham. His
transfer to Port Vale from Norrby was made permanent on 2 January 2015.
Manager Rob Page handed him an 18-month contract and stated that he hoped to turn the player into an asset for the club. He scored his first goal in professional football at
Vale Park on 7 February, in a 2–2 draw with
Bradford City. After the game Page defended his decision to restrict Campion's playing time despite his success at
reserve level, saying he did not want to "throw him in the deep end straight away". Page announced he would look to loan him out at the start of the
2015–16 season as
Uche Ikpeazu,
Louis Dodds,
Ebo Andoh and
A-Jay Leitch-Smith were all preferred ahead of Campion on the opening day of the season, and
JJ Hooper also joined the club two days later. He began training with
National League side
Torquay United on 22 October, and agreed a one-month loan deal with the club seven days later after "Gulls" manager
Kevin Nicholson was impressed by his character. After making one
substitute appearance he had a chance to establish himself in the first-team following a three-game suspension to
Tyrone Marsh. However, he
broke his nose on his second start for the club and had to be taken off early in the second half, and the injury then left him unable to feature for the rest of his loan spell. He was released by Port Vale in May 2016. Chairman
Norman Smurthwaite used
Twitter to express his view that Campion had been treated unfairly by former manager Page and said he hoped to bring the striker back for pre-season.
Ireland Campion signed with
League of Ireland Premier Division club
Sligo Rovers in August 2016. Manager
Dave Robertson said that "he really fits what we're looking for" as Campion scored on his debut, in a 5–0 win over
Wexford Youths on 5 August. He signed with
Cork City in November 2016, with manager
John Caulfield saying that "he’ll create lot of goals and score a lot of goals, and that’s what we need". He scored two goals in 23 appearances across the
2017 season, helping the "Rebel Army" to win both the Premier Division title and the
President of Ireland's Cup, though he was an unused substitute in
the final at
Turners Cross. On 4 November, he entered
the final of the
FAI Cup at the
Aviva Stadium as a substitute in
extra time, and went on to score the equalising goal of a 1–1 draw; Cork went on to win the trophy on penalties. On 2 January 2018, Campion joined
NIFL Premiership club
Linfield on loan for the rest of the
2017–18 season; manager
David Healy said "he's a player we know well and have seen play live several times". He scored two goals in 16 appearances for the "Blues" as they posted a fourth-place finish at the end of the
2017–18 campaign. He left Cork City on 26 July 2018. On 16 August 2018, Campion joined
Dublin club
St Patrick's Athletic on a contract to run until the end of the
2018 season. ==Style of play==