The 2003 All-Ireland Senior Hurling Championship (known for sponsorship reasons as the Guinness Hurling Championship) was the 117th since its establishment in 1887.

The first matches of the season were played in May 2003, and the championship ended on 14 September 2003.

Kilkenny went into the 2003 championship as defending champions, having won their twenty-seventh All-Ireland title the previous year.

The championship culminated with the All-Ireland final, held at Croke Park, Dublin.

Promoted from the All-Ireland Senior B Hurling Championship Regraded to the All-Ireland Senior B Hurling Championship Twenty two counties will compete in the All-Ireland Senior Hurling Championship: one team in the Connacht Senior Hurling Championship, ten teams in the Leinster Senior Hurling Championship, six teams in the Munster Senior Hurling Championship and five teams in the Ulster Senior Hurling Championship.