2003–04 Llanelli Scarlets season

Llanelli Scarlets
2003–04 season
ChairmanStuart Gallacher
Head coachGareth Jenkins
Celtic League1st
Celtic CupQuarter-finals
Heineken CupQuarter-finals
Highest home attendance10,800 vs Biarritz (9 April 2004)
Lowest home attendance2,460 vs Newport Gwent Dragons (20 September 2003)

The 2003–04 season was the inaugural season in the history of the Llanelli Scarlets rugby union team. They competed in the Celtic League, which they won, as well as the Celtic Cup and Heineken Cup, reaching the quarter-finals of both competitions. They played their home matches at Stradey Park along with Llanelli RFC, who had played there since 1879.