2008-09: Kevin Gagne made his QMJHL debut with Saint John as a 16-year-old and played for Canada Atlantic in the 2009 U17 World Hockey Challenge. In 48 games with the Sea Dogs he scored 3 goals with 3 assists and was +1 with 20 penalty minutes. Saint John finished third in the Atlantic Division and were swept by Cape Breton in the first round of the playoffs. Gagne was -1 with no points nor penalty minutes in four playoff games. He had 2 assists in five games for Canada Atlantic at the WHC.
2009-10: Gagne played 63 games for Saint John in his second QMJHL season. He scored 4 goals with 25 assists and was +39 with 40 penalty minutes. The Sea Dogs had the league’s best record and won the Atlantic Division in the regular season but lost to second-place Moncton in the QMJHL Finals. Gagne appeared in five playoff games, suffering a season-ending knee injury, and was +2 with 1 assist and 2 penalty minutes.
2010-11: Gagne was an assistant captain and skated in 59 games for Saint John in his third season with the Sea Dogs. Overshadowed on a talented defense corps that featured first round picks Nathan Beaulieu (Montreal) and Simon Despres (Pittsburgh), he scored 6 goals with 26 assists and was +37 with 34 penalty minutes. The Sea Dogs again had the QMJHL’s best record and defeated surprising Gatineau in the finals to reach the Memorial Cup. Gagne scored 2 goals with 5 assists and was +7 with 4 penalty minutes in 19 playoff games. The Sea Dogs defeated host Mississauga St. Michael’s in the Memorial Cup final. Gagne scored 1 goal and was -2 with 2 penalty minutes in four Memorial Cup games.
2011-12: Gagne skated in all 68 games for Saint John in his fourth QMJHL season as the Sea Dogs again finished with the league’s best record and rolled through the playoffs. He scored 9 goals with 26 assists and was +36 with 10 penalty minutes. Saint John won 16 of 17 games in the QMJHL playoffs and Gagne scored 2 goals with 13 assists and was +21 with 2 penalty minutes. The Sea Dogs came up short in their bid for a second Memorial Cup, falling to host Shawinigan in the semifinals (two days after beating the Cataractes in a round-robin game). Gagne had 2 assists and was +2 in four Memorial Cup games.
2012-13: Gagne signed a three-year entry-level contract with Anaheim in March 2013 and made his pro hockey debut with Ducks AHL affiliate Norfolk in April following an over-age season in the QMJHL. In five games with the Admirals he was -3 with 1 assist. Norfolk was fifth in the East Division; two points out of an AHL playoff spot. Gagne began the season in camp with the AHL’s Hamilton Bulldogs but was cut and returned to Saint John. He skated in 31 games with the Sea Dogs before being obtained by Rimouski in a December trade. In 62 regular season games between the two teams he scored 9 goals with 26 assists and was +36 with 10 penalty minutes. The Oceanic finished second in the East Division and lost to Gatineau in a first round playoff series. Gagne scored 1 goal with 1 assist and was -6 in six playoff games.
2013-14: Gagne provided playmaking from the blue line for Anaheim AHL affiliate Norfolk in his first pro season. Second amongst Norfolk defensemen with 19 assists, one less than team leader Alex Grant, he scored 3 goals and was -8 with 25 penalty minutes in 71 regular season games. Norfolk finished third in the East Division and reached the second round in the playoffs. Gagne played in 8 of 10 playoff games and was -2 with 1 assist.
2014-15: Gagne attended his second training camp with the Ducks before being assigned to AHL affiliate Norfolk. Playing a diminished role in his second year with the Admirals after the addition of veteran Brendan Bell, he scored 2 goals with 6 assists and was -21 with 16 penalty minutes in 57 games. Norfolk missed the AHL playoffs, finishing last in the East Division.
Gagne, though small in stature, plays a well-rounded two-way game. Not one to back down from a challenge, he makes a good first pass and works hard in all situations. On the powerplay, he has a great shot and moves the puck well. In his own zone, he attempts to keep the front of the net clear and works hard in the corners but is often at a disadvantage due to his size.
Gagne after being in limbo to start the 2015-16 season was loaned to Mora IK in Sweden's Allsvenskan on November 2nd. Mora IK, after a slow start, has turned things around and Gagne has been playing a top pairing role for the club. Now in the third year of his original three-year entry-level contract with Anaheim, he does not appear to have a future with the Ducks. His skating ability and offensive skills seem more suited to playing in Europe.