Leinster League Division One, as the name implies, is the first division of the Leinster League and started in the 1994/95 season.

Suttonians, Co. Carlow, Arklow, Mullingar, Garda, Navan, Naas, Wexford Wanderers, Portlaoise, Dundalk and Enniscorthy entered the division through the qualifying matches in the 1993/1994 season.

At the end of the season, Ashbourne were relegated to Division Two and Enniscorthy, Newbridge and Tullow were promoted, making it 14 teams once again for 2008/2009.

At the end of the season, Mullingar, Enniscorthy and Kilkenny were relegated to Division Two and Ashbourne and Wicklow were promoted.

Naas won promotion to AIB Division Three.