Mark Dennehy is the head coach for the Merrimack College hockey team. He was named the seventh head hockey coach in Merrimack College history on June 30, 2005. Dennehy came from the University of Massachusetts Amherst where he worked with current UMass Coach Don Cahoon from 2000-2005. 

Mark garnered Hockey East Coach of the Year staff member honors in 2002-03 and was involved in all aspects of coaching the Minutemen, including recruiting, video analysis, fund-raising, marketing, and on ice instruction. He was a part of one of the quickest rebuilding processes in the history of college hockey, when the UMass team advanced to the finals of the 2003 Hockey East Tournament in just the third season under head coach Don Cahoon and his staff. With the likes of All-American Thomas Pock, Greg Mauldin, and Nick Kuiper, UMass took Maine to three overtimes before losing in the finals.

Prior to his position at UMass, Dennehy worked for Cahoon at Princeton from 1994-99. He helped the tigers to three consecutive ECAC ‘Final Five’ tournaments in Lake Placid. In 1997-98 Dennehy contributed toward Princeton’s first ever ECAC championship and only NCAA appearance in the long distinguished history of the program. From there, he cut his teeth as the head coach at Fairfield University for the 1999-2000 before joining ‘Toot’ again at UMass.

Dennehy has recruited and/or coached two All-American players, two Hockey Humanitarian Award Finalists, three all-rookie team members, and four all-league selections. Six of his former players have signed NHL contracts. Jeff Halpern, the most prominent, served as the captain of the Washington Capitals during the 2005-06 season before signing with the Dallas Stars prior to the start of the 2006-07 season. He has also played for the U.S. National Team in the World Cup of Hockey, Olympics, and World Championships.

More recently, Dennehy created, founded, and directed the U.S. College Hockey Advancement Camp. The first of its kind in the east, the USCHA attracts prospects and their families from all over North America to the UMass Amherst campus. This prospect camp is fully staffed with college hockey coaches. The schedule includes practices, seminars, and games each day. The seminars include topics such as the NCAA Clearinghouse, Strength & Conditioning, and a panel discussion between the prospects, their parents, and college coaches.

A member of the American Hockey Coaches Association since 1994, Dennehy was named to the AHCA Boar of Governors in 2006. He has also volunteered for both Massachusetts Hockey and USA Hockey.

A native of Dorchester, Mass., Dennehy helped Boston College win three Hockey East regular season titles, played on the 1989-90 Hockey East Championship team and was a part of three NCAA qualifying teams, including the 1990 team which advanced to the NCAA Frozen Four at Joe Louis Arena in Detroit.

He then went on to play a season in Britain’s elite league for the Ayr Raiders in 1991-92. Dennehy parlayed that into a tryout with the Fort Wayne Comets in the IHL before trading in his skates for a whistle.

Mark's jersey was retired by Dorchester Youth Hockey in 2009.