2010-11: Matt Murphy played for the Fredericton Canadiens midget AAA team in the New Brunswick-PEI league and skated in the 2010 Canada Winter Games and 2011 U17 World Hockey Challenge tournaments. He scored 4 goals with 19 assists and had 10 penalty minutes in 33 regular season games for the Canadiens. Murphy scored 1 goal with 5 assists and 6 penalty minutes in six playoff games. Fredericton finished third in the Atlantic Region tournament. Murphy scored 2 goals with 4 assists and had 4 penalty minutes in seven games for Team New Brunswick in the U16 CWG. He had 1 assist and 6 penalty minutes in five games for Canada Atlantic at the WHC. Murphy was selected by Val-d'Or in the first round (fifth overall) of the 2011 QMJHL Entry Draft.
2011-12: Murphy played for Val-d'Or in the QMJHL as a 16-year-old rookie and represented Canada Atlantic in his second World Hockey Challenge tournament. He scored 3 goals with 13 assists and was -15 with 39 penalty minutes in 61regular season games. The Foreurs reached the playoffs — finishing second in the West Division — and Murphy was -5 with no points and 8 penalty minutes in four playoff games as Val'd"Or was swept by Halifax. In five games for Canada Atlantic he scored 1 goal with 1 assist and 6 penalty minutes.
2012-13: Murphy began the year with Val-d'Or before being acquired by eventual Memorial Cup champion Halifax in a multi-player trade in January. He scored 1 goal with 23 assists and was +2 with 20 penalty minutes in 40 games with the Foreurs prior to the trade. He scored 1 goal with 8 assists and was +20 with 16 penalty minutes in 29 regular season games with Halifax. Murphy had 2 assists and was +5 with 4 penalty minutes in 16 QMJHL playoff games and was +2 with no points and 4 penalty minutes in four Memorial Cup games. He was ranked 114th amongst North American skaters in Central Scouting's final rankings prior to the 2013 NHL Draft but was not selected.
2013-14:Murphy returned to Halifax for his first full season with the Mooseheads. He scored 10 goals with 26 assists and was +51 with 63 penalty minutes in 64 regular season games as Halifax cruised to a first-place finish in the Maritimes Division. Murphy was ranked 105th amongst North American skaters in Central Scouting's mid-term rankings prior to the 2014 NHL Draft.
A smooth skater with a solid frame, Murphy can contribute at both ends of the ice, using his size to break up an attack by the opposition and then jumping up to join or even lead the rush up the ice on the transition. His offensive game is coming along as he gets more confident, and he has great puck moving skills along with a heavy shot. A steady, physical force in his own end who can play plenty of minutes, Murphy is at his best when he keeps his game simple and doesn't try to do too much.