Addazio was a four-year starter at Central Connecticut from 1978 to 1981 and earned tryouts with the NFL's New England Patriots, USFL's Jacksonville Bulls and CFL's Ottawa Rough Riders.

Over twenty of his high school players earned places on the roster of college football programs.

Cheshire also won three consecutive state titles and was ranked in the top twenty-five high school football teams in the country under Addazio.

Starting in 1995, Addazio moved up to the college football ranks and had stints as a position coach with Syracuse, Notre Dame, and Indiana.

However, Temple transitioned to the tougher Big East Conference during the offseason, which forced just a 4–7 finish without bowl eligibility in the following year.

Following a dismal 2–10 season under Spaziani, Addazio made an immediate impact in his first year as Head Coach of the Eagles.

The feature component of Addazio's run-heavy offense, senior running back Andre Williams emerged as a standout player and rushed for 2,177 yards on the year.

The mark earned him a top-10 spot on the all-time NCAA record list for most rushing yards in a season, and the Doak Walker Award as the best running back in the country.

[5] Addazio and Boston College suffered a setback in 2015, as the Eagles finished with a 3–9 record and went winless in the ACC.

19 ranked Syracuse was the Eagles' last chance to re-enter the polls, however they dropped the matchup in a disappointing three-game skid to end the season.

[10] On October 10, 2018, the Boston College satirical newspaper The New England Classic released DazQuest, an Addazio-themed video game.

[11] Created with the interactive fiction software Twine, the game allows players to assume the role of Addazio as he embarks on a comedic adventure to retrieve the stolen campus statue of Doug Flutie.

[12] The game also features cameos from other real-life Boston College personnel such as hockey coach Jerry York, athletic director Martin Jarmond, and campus mascot Baldwin the Eagle.

Ten days after his firing from Boston College, Addazio was hired as the head coach at Colorado State University to replace Mike Bobo.