He signed for the town's club in 1993, aged 17, and went on to play his entire professional career with them. In 1995, at age 19, he became the first player to score a hat-trick in a Premiership final and also the youngest ever winner of the Harry Sunderland Trophy for man-of-the-match in Wigan's victory.
He was given a testimonial year in 2005 for his loyal service to Wigan Warriors, and despite that year being very successful for the team, it was a difficult season for Kris with him making only 15 appearances for the team through a knee injury. His testimonial match was played at the JJB Stadium on 29 January 2006 against the Huddersfield Giants. Wigan won this match 38–22.
Internationally he was capped 20 times by Great Britain, and won 10 England caps. The pinnacle of his international career, in which he was a main stay in the international setup, saw him captain the team against New Zealand 'A'. He scored three tries in this match.
He has twice been linked with a big money move to rugby union, in 2001 and 2005, but both times chose to remain faithful to his hometown club. One of these offers was to be part of the England Rugby Union team in the preparations for the 2003 World Cup.
Radlinski announced his retirement from the sport prematurely on 2 March 2006 due to persistent injuries. He had made 310 appearances for Wigan, scoring 183 tries. This brought down the curtain on a successful career during which the player was a loyal servant to his club and to the game of Rugby League.
In June 2006 Radlinski made the shock announcement that he would be coming out of retirement to help his old club Wigan Warriors. Kris had retired from Rugby League and left the Warriors, but after watching Wigan struggle in 2006's Super League XI he decided to come out of retirement to help them avoid relegation. His first match on his return, on 18 June 2006, saw the Wigan Warriors beat Catalans Dragons 24–18. He played the rest of the season for "no fee". Wigan stayed in Super League whilst Castleford Tigers were relegated.
Radlinski returned to Wigan during the 2009 season to take a scholarship coaching role. As well as publishing an autobiography entitled Simply Rad he was given a place on the England coaching staff for the 2009 Four Nations tournament. On 1 December 2009, Radlinski was appointed Rugby General Manager at Wigan and the right hand man to new head coach Michael Maguire but will also continue his scholarship role as well.