York was selected in the seventh round of the 1990 NHL Entry Draft by the Detroit Red Wings. His first NHL game was played during the 1992–93 NHL season when he suited up for the Red Wings December 3, 1992 against the Minnesota North Stars. He scored his first NHL goal April 10, 1994 against fellow Nepean native Fred Brathwaite of the Edmonton Oilers. Despite excelling in the minors, York found it difficult to crack a deep Detroit line-up and, after playing only nineteen games over three seasons for the Red Wings, he was traded to the Mighty Ducks of Anaheim April 5, 1995 along with Mike Sillinger in exchange for Stu Grimson, Mark Ferner, and a draft pick. In Anaheim, York was able to establish himself as an NHL regular and turned in a solid season in 1995–96, posting 3 goals and 21 assists for 24 points in 79 games. York was traded to the Ottawa Senators on October 1, 1996 with Shaun Van Allen in exchange for Ted Drury and the rights to Marc Moro. Then-Ottawa general managerPierre Gauthier had gained familiarity with York in his previous job as Anaheim's assistant GM. Playing in his hometown of Ottawa, York hit his stride as a quality NHL player, establishing himself as a steady 2 way defenceman on an up-and-coming Senators team. In 1998–99, he enjoyed his finest offensive season as he recorded 35 points to lead all Senators' defencemen in scoring. He spent five steady seasons in Ottawa where the club made the playoffs each year York was there before becoming an unrestricted free agent in 2001. York returned to Anaheim as a free agent for the 2001–02 campaign, signing a three-year, $6 million contract. He turned in another solid year but was traded at the start of the 2002–03 season to the Nashville Predators. York lead the Predators with the top plus minus in his first year with the club and helped Nashville make the playoffs for the first time in franchise history the following year. Many figured that the 2004–05 NHL lock-out would end his NHL career, as it did for many veteran players; after not playing in 2004–2005 due to 3 major surgeries and the passing of his father, York signed with HC Lugano for the 2005–06 season, where he would win the Swiss League championship. He performed well enough to earn another chance in the NHL, signing with the Boston Bruins for the 2006–07 season and appearing in 49 games with Boston. York suffered 3 knee injuries that season which ended his career. In 757 NHL games over 13 seasons, York recorded 42 goals and 187 assists for 229 points, along with 621 penalty minutes. He added 2 goals and 9 points in 34 playoff games, getting as far as the second round once.
Post-retirement
York started his broadcasting career in 2008 on Ottawa's all-sports radio station, TSN 1200 after completing the NHLPA life after hockey broadcasting program at Quinnipiac University. From 2008 to 2013 York co-hosted the daily afternoon-drive show The Healthy Scratches and later went on to co-host the mid morning show, In The Box, both with Steve Lloyd. York also dabbled in writing as well with the Ottawa Sun where he wrote his weekly column, the York State of Mind during his time on Ottawa Sports radio. In 2011, York also began appearing on Sportsnet television broadcasts for Ottawa Senators games, adding commentary with co-host Ian Mendes, and later with Shawn McKenzie. With the move of the Senators to TSN in 2014 York took on a new larger role with Sportsnet as the television colour analyst for the Montreal Canadiens with John Bartlett. York also has begun working on Hockey Night in Canada as a colour analyst. On July 19, 2017, York as part of an ownership group, purchased the Kemptville 73's of the Central Canada Hockey League, from former NHL goaltender Ron Tugnutt. York was also installed as the team's director of hockey operations.