Campion is one of three State of Origin representative products from
Sarina State High School (along with
Dale Shearer and
Wendell Sailor), and one of four from the
Sarina Crocodiles (along with Shearer, Sailor and
Martin Bella). Campion made his début for the
Gold Coast Seagulls in
1993, and went on to play 44 games for the club before signing with St. George for the
1996 season. He played in the in the Dragons' 8–20 loss to
Manly in the
Grand Final at the
Sydney Football Stadium. It would be his last game for St. George as he had signed to play for the
Adelaide Rams in the new
Super League competition in 1997. After joining the Rams, Campion was one of the team's stand-out players in the club's first season. He would make his representative début for Queensland during the
1997 Super League Tri-series that year but sensationally was told by Rams coach
Rod Reddy that he was not part of his plans for the club in 1998. After leaving Adelaide, Kevin Campion was snapped up by
Brisbane Broncos coach
Wayne Bennett, and went on to play 80 games for the club between 1998 and 2000, including the
1998 and
2000 NRL Grand Finals. He scored a try for Brisbane in their 38–12 win over the
Canterbury-Bankstown Bulldogs in the 1998 decider. Campion then signed with the
New Zealand Warriors in 2001 and went on to play at lock forward in their
2002 NRL Grand Final loss to the
Sydney Roosters. At half-time in that match, coach
Daniel Anderson attempted to inspire the team by playing a mock commentary track of the Warriors scoring "the greatest try ever scored". Campion picked up the tape recorder, smashed it on the ground and gave the team an inspired speech instead. This appearance made Campion one of only five players who have played in Grand Finals for three clubs during his career. Campion also represented
Queensland on six occasions: four times in the annual
State of Origin series, and twice in the
Super League Tri-series. He also helped
Ireland to the quarter-finals in the
2000 World Cup. Whilst at the New Zealand Warriors, Campion was co-captain with
New Zealand international halfback
Stacey Jones. ==Retirement==