Major American Football Leagues have been played outside of the USA since the World League of American Football in 1991.
[World Pro 1] World League of American Football (2018) WLAF Logo [Internet] Available from: http://www.worldleagueofamericanfootball.com/sitebuildercontent/sitebuilderpictures/WLAFlogo.gif [Accessed 23 April 2018]
Here are the Final standings and playoff results of each of the World Pro Leagues since the World League of American Football in 1991 and 1992. American Football League of Europe 1993-1995, WLAF again 1995-1997, NFL Europe 1998-2007, United Football League (USA) 2009-2011, Elite Football League of India 2012, Lingerie Football League Canada 2012-13, Legends Football League Australia 2013-14, China Arena Football League 2016 & 2019, Pretty Girls Football League (Mexico) 2017, as well as the International-only seasons played by the Hamburg Blue Devils 1993 and Amsterdam Crusaders 2018.
There were no Irish teams in these leagues unless you include the EuroSteelers of the European League (UK Conference) in 1993 (precursor to AFL Europe). the four teams of the UK Conference were intended to represent the four regions of the UK, with the EuroBears, EuroRaiders and EuroMonarchs the other three. The Pittsburgh Steelers were the designated home team for the NFL game in Dublin with the Chicago Bears.
World Pro American Football Leagues (Bowl Games):
World Pro American Football Leagues (Overviews):
World Pro American Football League Seasons:
 World League of American Football (2020) 96claymoresawayjersey50rs.jpg.w300h350 [Internet] Available from: http://www.worldleagueofamericanfootball.com/sitebuildercontent/sitebuilderpictures/.pond/96claymoresawayjersey50rs.jpg.w300h350.jpg [Accessed 17 September 2020]