|No. of teams||23|
|Recent Champions||Ville-Marie Pirates (2019)|
|Most successful club||Bradford Rattlers (3)|
The Greater Metro Junior A Hockey League is an independent Junior "A" ice hockey league. They were founded in 2006.
In revolt to Hockey Canada's Canadian Development Model and their banning of European players below the Major Junior level, the GMHL was founded with seven teams during the fall of 2006. The original teams were the Bradford Rattlers, Deseronto Thunder, King Wild, Nipissing Alouettes, Richmond Hill Rams, South Muskoka Shield, and Toronto Canada Moose.
In five years of operation, the league had doubled in size. Bradford won the league playoffs in 2007 and 2008, South Muskoka won in 2009, Deseronto won it in 2010, and 2007 expansion team Elliot Lake Bobcats took home the Russell Cup in 2011.
As of 2011, five of the original teams are still in operation: Bradford, Deseronto (now called the Storm), King (now known as the Lefroy Wave), South Muskoka, and Toronto. Nipissing and Richmond Hill both folded after three seasons, but Nipissing was replaced in 2010 by the Sturgeon Falls Lumberjacks in their hometown.
The league had boasted two teams of foreigner-only teams, Russians on the Shelburne Red Wings (2010-2014) and Americans on the Orangeville Americans (2011-2015). Hockey Canada and the GMHL have always been at odds. In 2007-08, Hockey Canada initiated a policy of a quarantine system on players, officials, and coaches involved with the GMHL. In the Summer of 2008, this was investigated by the Canadian Government and deemed illegal. Despite this, intimidation has persisted. During the 2010-11 season, this situation grew extreme in Shelburne and resulted in the Mayor of Shelburne forcing a sitdown between the town, Hockey Canada, and the GMHL.
As of September 2011, the league is operating in its sixth season with fourteen active franchises and two dormant franchises set to operate in 2012.
For 2015-16, the league is scheduled to have 34 franchises including 11 expansion teams and two teams on hiatus.
In late October or early November 2015 the Brantford Steelfighters folded.
On March 11, 2017 the league announced the addition of the Ville-Marie Pirates to the league for the 2017-18 season.
On August 31, 2017 the league announced that the Parry Sound Islanders were taking a leave of absence for the 2017-18 and would be able to return to the league for 2018-19. On November 22, 2017 the league announced the Fergua Force were removed from the league and would not be allowed to return for the 2018-19 season.
In March of 2019 postings on the St. George Ravens twitter page indicated that Tilsonburg was forced to forfeit games 3 and 4 of their semifinal playoff series due to a lack of players caused by food poisoning. Later reports indicated the team may have in fact folded.
On January 23, 2019 the league announced the addition of the Bancroft Rockhounds, which will be based out of the North Hastings Community Centre in Bancroft, Ontario. The team will start play with the 2019-20 season.
On June 13, 2019 it was announced that the Western Provinces Hockey Association teams that had been previously affiliated with the Western States Hockey League for the 2018-19 season would become affiliated with the GMHL and form the GMHL's Western Division. By early July the WSHL had two teams, the Edson Aeros and Meadow Lake Mustangs that had opted stay with the WSHL and announced the formation of new teams in Cold Lake and Hinton, Alberta, The previous teams in those towns apparently left a trail of unpaid bills 
On May 10, 2021, the Toronto Predators announced they were relocating to the Meridian Credit Union Arena in Niagara-on-the-Lake, Ontario for the 2021-22 season and will be renamed the Niagara-on-the-Lake Predators.
|High Prairie Red Wings||2019||High Prairie, Alberta||High Prairie Sports Palace|
|Northern Alberta Tomahawks||2019||Enoch, Alberta||Enoch Recreation Centre|
|Slave Lake Icedogs||2019||Slave Lake, Alberta||Multi-Rec Centre|
2019-20 Relocated, renamed, or fold prior to or during season
|Cold Lake Wings||2019||Cold Lake, Alberta||Imperial Oil Place||become Edmonton Academy Wings|
|Edmonton Academy Wings||2019||Edmonton, Alberta||none||unable to secure lease take spot of former Rosetown Jr. Red Wings as High Prairie Red Wings|
|Enoch Tomahawks||2019||Enoch, Alberta||Enoch Recreation Centre||renamed Northern Alberta Tomahawks|
|Hinton Wildcats||2019||Hinton, Alberta||could not secure lease for 2019-20 and fold|
|Ottawa Sharpshooters||2018||Almonte||Almonte Community Centre||removed from league January 3, 2020 when ownership folded team.|
|Rosetown Jr. Red Wings||2019||Rosetown, Saskatchewan||AGT Foods Centre||relocated to High Prairie, Alberta then replaced by former Edmonton Academy Wings franchise as High Prairie Red Wings|
Awarded teams that never played
- Downsview Spitfires (2014)
- Elliot Lake Bobcats (2015) originally announced as returning then disappear
- Halton Huskies (2011) awarded for 2011-12 season; then don't play
- 2007 Bradford Rattlers
- 2008 Bradford Rattlers
- 2009 South Muskoka Shield
- 2010 Deseronto Storm
- 2011 Elliot Lake Bobcats
- 2012 Sturgeon Falls Lumberjacks
- 2013 Bradford Rattlers
- 2014 Bradford Bulls
- 2015 Temiscaming Titans
- 2016 Tottenham Steam
- 2017 Niagara Whalers
- 2018 Almaguin Spartans
- 2019 Ville-Marie Pirates
- 2020 Playoffs cancelled prior to final round
- 2021 Playoffs cancelled (High Prairie Red Wings win Western Division playoffs)
- List of Greater Metro Junior A Hockey League standings
- List of Greater Metro Junior A Hockey League team names
- All-Time GMHL Standings