2003–04 Celtic League

The 2003–04 Celtic League was the third Celtic League season, and the first following the formation of the five regional rugby sides in Wales. The Celtic League, having previously been played as a pool stage followed by knockout rounds was restructured into a typical league system, based on home and away games only. The league was won by the Llanelli Scarlets, with all the other Welsh regions finishing in the top 6. Following this season, the Celtic Warriors were bought-out and disbanded by the Welsh Rugby Union, and in subsequent years, only four Welsh sides have competed.

Leading scorers
Note: Flags to the left of player names indicate national team as has been defined under IRB eligibility rules, or primary nationality for players who have not yet earned international senior caps. Players may hold one or more non-IRB nationalities.