The Sea Dogs are the fruit of the 2005 expansion.

During their first ever QMJHL Entry Draft in June 2005, the Sea Dogs selected defenseman Alex Grant first overall. They talked first in 2006 and 2007 and chose Yann Sauvé and Simon Després. Later in 2014 and 2015, they had the chance to draft 1st, and their picks were successively Luke Green and Joseph Veleno (a 15-year old categorized as an exceptional underage player). The quality of their draft picks in the past years have generated great hockey seasons! Later, in 2019, Joshua Roy became the 6th player to be selected #1 in the QMJHL, by the Saint John Sea Dogs.

After the 2021-22 season, the Sea Dogs acquired a phenomenal number of championships:

* 4 Jean-Rougeau Trophies, as regular season champions (2009-10, 2010-11, 2011-12, 2016-17)

* 4 participations into the President Cup Final Series including 3 championships (2011, 2012, 2017)

* 4 participations into the Memorial Cup tournament, winning the ultimate title in 2011 and 2022.

Most part of the championships listed above, were achieved under Head Coach Gerard Gallant.

During the 2019-20 regular season, with 58 points, William Villeneuve broke the franchise record for a defenseman, previously established by Nathan Beaulieu in 2011-12 with 52.

In 2022, Sea Dogs fans were quick to overlook the early elimination of their favourites in the first round of the QMJHL playoffs. Acting as the host club for the Memorial Cup, they won the Canadian Hockey League Grand Final at TD Station in Saint John in front of a sold out crowd of 5,849 on Wednesday, June 29, 2022. This 6-3 victory against the Hamilton Bulldogs (OHL), was their second quest for the Memorial Cup, after winning it in 2011. Forward William Dufour scored 7 goals on 31 shots in only 4 games of the tournament and was named the "Most Valuable Player" of the tournament.

The team's notables over the years include: Simon Després, Nathan Beaulieu, Jonathan Huberdeau, Mike Kelly, Gerard Gallant, Charles Coyle, Thomas Chabot, William Dufour...