He played youth football for USL Dunkerque, before playing college football in the United States for Belhaven Blazers, UC Santa Barbara Gauchos, Baton Rouge Capitals, and Ventura County Fusion. He signed with English club Port Vale via Swedish club Norrby IF in 2014. He was loaned out to Torquay United in November 2015, and after being released by Port Vale signed with Irish club Sligo Rovers in August 2016. He switched to Cork City three months later.
Campion was born on 10 March 1990 in Levallois-Perret, France. He played in the youth sides of USL Dunkerque from 2004 through 2010 and captained the under-18s in the Coupe Gambardella.
He left his native France to attend college in the United States at Belhaven University in Jackson, Mississippi. He was a student-athlete, playing for the Belhaven Blazers men's soccer team while on campus. In his two years there, he appeared in 36 games for the Blazers, scoring 21 goals and assisting on 5 others. Campion then enrolled at the University of California, Santa Barbara, where he played for the UC Santa Barbara Gauchos men's soccer team for his final two years of eligibility. With the Gauchos, he appeared in 25 games, collecting 13 goals and 3 assists.
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.
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.
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 AJ 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.
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".
In September 2014, the Port Vale website described him as "a strong target man, who is good at holding up the ball, can finish well when given the opportunity, and due to his size is also an aerial threat".As of 10 May 2017.
USL Premier Development League Southern Conference Team of the Year: 2011
with Norrby IF
Swedish Football Division 2 Västra Götaland champion: 2013