The All-Ireland Junior Cup, known as the Energia Men's Junior Cup for sponsorship reasons, is an annual knockout competition for rugby union clubs in Ireland. The top 4 Junior clubs from each of the 4 provinces qualify for the competition each season.
Beginning in 2005, the competition consisted of just 8 teams for the first season and was won by Rainey Old Boys from Ulster. It was expanded to 16 teams from the second season onwards. In the 20 seasons of the competition it has been dominated by teams from Leinster who have won it 13 times. Tullamore and Ashbourne have the most titles with 3 each.