2010-11: Colin Sullivan played for Avon Old Farms (CT) prep school. In 27 games, he scored 3 goals and added 12 assists for 15 points. Sullivan has committed to Yale University for the 2011-12 season.
2011-12: Sullivan played his senior year of hockey at the Avons Old Farms Prep school. The big defenseman work really hard on and off the ice to improve his strength and overall game. He finished the season, scoring seven goals along with nine assists while taking no penalties. Sullivan was named to the 2012 Boys’ Hockey All-New England Team by the NESPAC coaches association.
2012-13: Sullivan skated in 32 of 38 games for defending national champion Boston College as a freshman. He had 1 assist and was -4 with 6 penalty minutes in limited minutes for the Eagles. Boston College finished second in Hockey East and received an at-large bid to the NCAA tournament after a loss to Boston University in the Hockey East semifinals. BC lost to Union, 5-1, in the NCAA East Regional semifinals.
2013-14: Sullivan left Boston College in October to skate for the USHL’s Green Bay Gamblers. In 41 games he scored 2 goals with 6 assists and was -2 with 46 penalty minutes. The Gamblers finished fourth in the Eastern Conference, falling to Clark Cup champion Indiana in a first-round playoff series. Sullivan was -1 with no points and 2 penalty minutes in four playoff games. In March 2014 he committed to playing college hockey at Miami University in 2014-15.
2014-15: Sullivan skated in nine games for Miami University as a sophomore, missing much of the season after an early season injury. Playing both defense and forward for the RedHawks, he was +3 with 4 penalty minutes, recording his only point (an assist) in a 7-5 loss to Western Michigan in Game 2 of their three-game NCHA quarterfinal series. Miami finished second in the NCHC in the regular season and earned an NCAA tournament bid after defeating St. Cloud State, 3-2, in the NCHC tournament championship game. Eventual national champion Providence topped the RedHawks, 7-5, in a wild East Regional semifinal game.
2015-16: Sullivan skated in 15 games for Miami University in his junior season. He scored 1 goal and was -7 with 6 penalty minutes. The RedHawks finished fifth in the National Collegiate Hockey Conference, falling to Minnesota-Duluth in the NCHC quarterfinals.
Sullivan is an exceptional skater, with tremendous endurance and a strong work ethic. His smoothness and edge work is something Miami University could utilize on their back-end next season. His physical conditioning is top-notch and he has a strong work ethic and tons of character. He is not gifted offensively, and his work in the defensive zone is questionable, as he has a tendency to make poor decisions and is inconsistent with his positioning. He needs to learn to read the play in front of him better and react quicker if he hopes to continue developing into the next level of hockey.
Sullivan skated in 15 of 36 games for the Miami University RedHawks in 2015-16 as a junior. A late-round project pick out of prep school due to his mobility when he was selected by Montreal in the 2011 NHL Draft, Sullivan has yet to make an impact at the college level and his pro potential appears limited.