2007-08: Matt Carey played for the Hamilton Junior Bulldogs minor midget AAA team in Ontario. He scored 13 goals with 14 assists in 48 games.
2008-09: Carey skated for the Alliance Hockey champion Hamilton Reps midget AAA team that advanced to the Telus Cup. He scored 16 goals with a team-leading 28 assists and 48 penalty minutes in 36 regular season games. Carey scored 8 goals with 9 assists and 22 penalty minutes in 11 playoff games. After finishing third in Central Region round robin play the Reps defeated Sault Ste. Marie and Oakville, scoring eight goals in both games, to reach the Telus Cup. Carey scored 1 goal with 2 assists and 6 penalty minutes in five games at the 2009 Telus Cup as Hamilton finished 0-4-1.
2009-10: Matt Carey played five games for the Burlington Cougars on a team with his older brother Greg Carey (PHO) before being dealt to the rival Hamilton Red Wings in the junior A Ontario Junior Hockey League. He was +1 with no points nor penalties in his time with the Cougars. Matt Carey scored 7 goals with 6 assists and was +5 with 20 penalty minutes in 20 regular season games with Hamilton. In 10 playoff games he scored 1 goal with 2 assists and was -1 with 20 penalty minutes.
2010-11: Carey was the second-leading scorer for Hamilton behind University of Michigan recruit Zach Hyman (FLA) in his second OJHL season with the Red Wings. In 45 regular season games he scored 25 goals with 59 assists and 40 penalty minutes. Hamilton finished fourth in the West Division and in seven playoff games Carey scored 3 goals with 2 assists and 10 penalty minutes.
2011-12: Carey returned to Hamilton for his third OJHL season and was acquired by the Toronto Junior Canadiens in mid-season to boost that team's playoff push. Skating with former Reps teammate Andrew Radjenovic in Hamilton he had 17 goals with 21 assists and 8 penalty minutes in 23 games before being traded (Radjenovic was dealt to Markham in a separate deal). Carey scored 16 goals with 15 assists and 24 penalty minutes in 25 regular season games for Toronto. In 10 playoff games, he scored 9 goals with 5 assists and 18 penalty minutes. In April he committed to playing college hockey at St. Lawrence in 2012-13.
2012-13: Carey attended St. Lawrence University as a freshman but was ruled ineligible by the NCAA and did not play in any games for the Saints.
2013-14: Carey finally had the opportunity to skate alongside his brother Greg Carey at St. Lawrence and the two finished one-two for the Saints in scoring, playing on the team's top line. A red-shirt freshman, Matt Carey scored 18 goals with 19 assists and was -8 with 47 penalty minutes in 38 games (Greg, a senior, was the NCAA's third-leading scorer behind Boston College's Johnny Gaudreau (CGY) and Kevin Hayes (CHI)). St. Lawrence finished eighth in ECAC Hockey. The Saints swept Brown in a first round playoff series before falling to Colgate in the quarterfinals. Following the playoffs Matt Carey signed a two-year entry-level contract with Chicago in March 2014; foregoing his final three seasons of college hockey.
Chicago signed Matt Carey to a two-year entry-level contract on March 20th, 2014, one day after his older brother, Greg Carey, signed with Phoenix.