The 2018 Celtic Cup is the inaugural edition of the Celtic Cup rugby union competition, which features development regional and provincial teams from Ireland and Wales.

Leinster A won the inaugural edition, beating Scarlets A in the final.

The Irish Rugby Football Union and the Welsh Rugby Union created a new development competition, the Celtic Cup, for the emerging professional players from the four Irish provinces and four Welsh regions, announcing the tournament in August 2018.

The tournament, which features development squads from Pro14 teams Connacht, Leinster, Munster, Ulster, Cardiff Blues, Dragons, Ospreys and Scarlets, aims to provide a learning environment for development players, coaches and referees by recreating the week-to-week challenges presented by senior professional rugby.

The eight teams were divided into two conferences of four Welsh regions and four Irish provinces.