31 August – The remains ofBelfast motherJean McConville were found 31 years after she was abducted and murdered by theProvisional IRA, who accused her of being a British Army agent.
15 September – For the first time, theAll-Ireland Football Final was contested by two teams from the same province.Tyrone were victorious overArmagh in the first All-Ulster Final.
31 October – The2003 Derrybrien landslide occurred on the side of Cashlaundrumlahan, a hill nearDerrybrien inCounty Galway. It was focused around turbine 68 in the Derrybrien wind farm, and disrupted further construction.
27 November – The people of Northern Ireland went to the polls. TheDemocratic Unionist Party andSinn Féin made massive gains at the expense of more moderate unionist and nationalist parties.
TheLeague of Ireland moved from a predominantly winter season to a Scandinavian-style summer season.Bohemians won the transitional 2002/03 season andShelbourne won the 2003 championship.