Celtic Challenge

The Celtic Challenge is a cross-border women's rugby union competition that will be held annually, launched in 2023. Designed to develop players for the Celtic nations of Ireland, Scotland and Wales, the inaugural pilot edition featured a double round robin between three teams, one from each participating union. From 2024 the competition will involve six teams, two from each participating union. Beginning with the 2024–25 season, the competition will maintain its six-team setup, transitioning into a full home-and-away round-robin format. The winners will be determined by standings at the end of the season.

The three participating unions fund the competition, with further development funding from World Rugby.

All time
A total of 9 clubs have been involved in since the league's inception in the 2023 season.

Below, the 2023–24 clubs are listed along with the number of full seasons they've competed in. Current clubs are shown in bold. The seasons each club has participated in, including the present one, are displayed in the last column.

2023 competition
The inaugural year of the competition in 2023 consisted of three teams: The first edition consisted of six matches in a double round robin:

2023–24 competition
In November 2023 it was announced that for the second season, the competition would expand to six teams.

In December it was announced that the 2023–24 competition will run from December to March 2024 and will be contested by six teams:
 * 2 teams from Ireland, the Clovers and the Wolfhounds.
 * 2 teams from Wales, Brython Thunder and Gwalia Lightning.
 * 2 teams from Scotland, Edinburgh Rugby and Glasgow Warriors

The teams will play each other once, either home or away, across five rounds before play-offs to decide a champion in March 2024.