Tournament Director David Jordan said; "The importance of this milestone is not to be underestimated, attendances have increased significantly over the past three seasons and fans are endorsing the exciting brand of rugby played in the Celtic League by coming to watch a game.
"We have seen the attendance record at a single game broken five times already this season, and at 15,183 is around 50% higher than the best recorded last season. Overall attendances have increased almost 20% compared to last year with the average Celtic League gate now well over 5,000.
"Over the same period of time we have seen the national teams prosper; Wales completed an RBS Six Nations Grand Slam last season and Ireland took the Triple Crown trophy this year whilst Scotland recorded victories over England and France in the same tournament.
"With three rounds of Celtic League games still to be played there are plenty of meaningful matches to come - not only is Heineken Cup qualification for next season still to be determined but also the Celtic League title itself, so we can expect more bumper crowds for the remainder of the season."