Bio

Coach Sullivan is now entering his 6th total, fifth consecutive season at Fitchburg State University, and he has played a pivotal role in the development of the Falcons football program since arriving in March of 2022.  He previously spent the 2019 season as Fitchburg State's Associate Head Coach and Defensive Coordinator before returning to a role in 2022.  During his time in Fitchburg, he has served as Offensive Coordinator, Interim Head Coach, Assistant Head Coach, Defensive Coordinator, and currently Associate Head Coach/Defensive Coordinator. 

Sullivan is a veteran coach with more than 43 seasons of experience as a defensive coordinator across the highschool and college football scene, including over 15½ seasons as a DII/DIII collegiate head football coach. He has overseen one of the most significant defensive turnarounds in recent program history.

In 2025, the Falcons fielded one of the nation's premier defenses, leading all of NCAA Division III in passing defense by allowing just 105.7 passing yards per game. Fitchburg State also ranked second in the MASCAC in scoring defense (18.2 points per game) and total defense (255.4 yards per game). The Falcons led the conference with 22 takeaways and 15 interceptions while tying for the conference lead with three defensive touchdowns.

The foundation for that success was established in 2023 when Fitchburg State ranked ninth nationally in Division III in passing defense, reduced its points allowed by 14 points per game from the previous season, and surrendered its fewest yards per game since 2018. In 2024, the Falcons produced the MASCAC Defensive Player of the Year, Cam Monette.

Over his four completed seasons at Fitchburg State, he has helped transform the Falcons into one of the top defensive programs in the MASCAC, culminating in a nationally-ranked unit and the nation's top pass defense in 2025.

Prior to Fitchburg State: 

In between his stints at Fitchburg, Sullivan served as Defensive Coordinator at Worcester Academy from 2020-22. 

Prior to the Falcons 2019 season, Sullivan enjoyed a highly successful five-year tenure as Defensive Coordinator at Nichols College from 2013-18. In 2018, Nichols finished with the No. 1 pass defense in the conference and the No. 10-ranked pass defense nationally. The Bison also finished among the conference leaders in several major defensive categories. In 2017, Nichols again led the conference in pass defense and ranked No. 22 nationally while four defenders finished among the conference's top 10 statistical leaders. During his tenure, he coached a linebacker who established the school's all-time tackles record with 385 career stops and helped guide the program to its best record since 2003.

Before Nichols, Sullivan spent seven seasons as Associate Head Coach and Defensive Coordinator at Worcester State University. The Lancers routinely ranked among the conference leaders in major defensive categories and advanced to the 2011 ECAC Bowl Championship Game. In 2010, one of Sullivan's linebackers led all of NCAA football with 168 tackles.

Sullivan also served as Head Football Coach at Framingham State University from 2002-06, where he helped establish the foundation for the program's future success while serving in multiple roles, including offensive coordinator, defensive coordinator, and recruiting coordinator.

His collegiate coaching experience also includes positions at Worcester State from 1999-2002 and at University of Massachusetts Lowell from 1997-99, where he served as Offensive Coordinator, Director of Football Operations, Defensive Line Coach, and Special Teams Coordinator.

Before entering the college ranks, Sullivan compiled 15 seasons as a Massachusetts high school head coach, leading programs at Amesbury, Westfield, Ayer, Murdock, and Keefe Technical. His accomplishments included earning Coach of the Year honors in 1991 and selection to coach in the 1992 Shrine All-Star Game. He also served as an assistant coach at St. Bernard's High School and Marlboro High School.

The son of Massachusetts Hall of Fame Football Coach Peter Sullivan, former King Philip, Wayland and Woburn head coach, Mark grew up in Marlboro, Mass. and attended UMass Amherst where he played nose tackle for two seasons, before his career ended short due to two season ending knee injuries. Sullivan is a member of the American Football Coaches Association (AFCA), and throughout a coaching career spanning more than four decades, Sullivan has consistently developed championship-caliber defenses, mentored award-winning student-athletes, and established himself as one of the most experienced and respected football coaches in New England.