2008-09: Samuel Henley appeared in 13 regular season games and six playoff contests with the midget AAA Amos Forestiers in Quebec as a 15-year-old. He scored 1 goal with 4 assists and 2 penalty minutes in the regular season and scored 1 goal with 2 assists in the playoffs. Henley was selected by Lewiston in the third round (39th overall) of the 2009 QMJHL Entry Draft.
2009-10: Henley played in 63 of 68 regular season games and all four playoff contests for the Lewiston MAINEiacs in his first season in the Quebec Major Junior Hockey League and played for Canada Quebec in the 2010 World Hockey Challenge U17 tournament. He scored 4 goals with 9 assists and was minus-13 with 22 penalty minutes during the regular season. Lewiston finished last in the Central Division but edged Baie-Comeau for the last playoff spot. The MAINEiacs were swept by Drummondville in the first round and Henley was minus-2 with 1 assist and 2 penalty minutes. He scored 1 goal with 14 penalty minutes in five games for Canada Quebec at the WHC.
2010-11: Henley provided supplementary scoring in a lower line role as Lewiston was one of the most improved teams in Canadian junior hockey in his second season. He scored 13 goals with 18 assists and was +13 with 37 penalty minutes in 64 games. In what would be the franchise's last season, Lewiston finished second in the East Division and advanced to the playoff semifinals; falling to Memorial Cup-bound Saint John in four straight games. Henley had 2 assists and was minus-1 with 4 penalty minutes in 15 playoff games. He was ranked 156th amongst North American skaters in Central Scouting's final rankings but was not selected in the 2011 NHL Draft.
2011-12: Henley was selected by Val d'Or in the dispersal draft of Lewiston players; joining his older brother Cedrick Henley, a 2010 draft pick of Buffalo, with the Foreurs. Samuel Henley scored 13 goals with 14 assists and was +6 with 71 penalty minutes in 63 games during the regular season. Val d'Or was second in the West Division before being swept by Rimouski in a first round playoff series. Henley had an even plus/minus in the four game series and scored 1 goal with 2 assists and 9 penalty minutes.
2012-13: Henley was named an assistant captain and displayed an offensive touch to his game on a Val d'Or team that tied Moncton and Baie-Comeau for third most goals (274) in the QMJHL. He scored 22 goals with 23 assists despite missing 10 games and was +14 with 59 penalty minutes. The Foreurs finished fourth in the West Division and reached the second round in the playoffs. Henley scored 1 goal with 2 assists and was an even plus/minus with 6 penalty minutes in 10 playoff games.
2013-14: Henley attended the Washington Capitals training camp but was not signed and returned to Val d'Or for what would be a memorable overage season. He was the Foreurs' fifth-leading scorer during the regular season and played a key role in the post-season as Val d'Or captured the QMJHL's President's Cup and reached the Memorial Cup semifinals. A team captain, Henley scored 30 goals with 39 assists and was +33 with 42 penalty minutes in 51 games; missing 17 games. He scored 8 goals with 20 assists and was +10 with 25 penalty minutes in 24 games in the QMJHL playoffs and scored 1 goal with 1 assist and was +1 with 2 penalty minutes in four Memorial Cup games. The Foreurs defeated Edmonton, 4-3, in round robin play but were on the short end of the same score against the eventual Memorial Cup champion Oil Kings in the semifinals three nights later. Henley signed a three-year entry-level contract with Colorado on April 28th.
A big forward who is not afraid to mix it up, Henley does all the little things well, from playing well defensively to working hard in the corners. Not a pure talent offensively, Henley's effective due to his hard work on the ice, but needs to continue to add strength to his frame.
Colorado signed Henley to an entry-level contract on April 28th, 2014