| Leinster League Division One | 
|---|
| Founded | 
| 1994 | 
| Nation | 
| Relegation To | 
| Leinster League Division Two | 
| Number of Teams | 
| 14 | 
| Current Champions (2007–08) | 
| Cill Dara RFC | 
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.
The number of teams in the division was reduced from 14 to 12 in the 2007/08 season, but this was reversed in the 2008/09 season.
2008/2009 Season
- Boyne
 - Cill Dara
 - Dundalk
 - Enniscorthy
 - Garda
 - Monkstown
 - Navan
 - Newbridge
 - Portlaoise
 - Seapoint
 - Skerries
 - Tullamore
 - Tullow
 - Wicklow
 
2008/2009 Table
| 2008-2009 Leinster League Division One League Table | |||||||||
| Club | Played | Won | Drawn | Lost | Points for | Points against | Points difference | Bonus Points | Points | 
|---|---|---|---|---|---|---|---|---|---|
| Navan | 7 | 7 | 0 | 0 | 219 | 31 | 188 | 3 | 31 | 
| Seapoint | 7 | 6 | 0 | 1 | 141 | 71 | 70 | 2 | 26 | 
| Monkstown | 7 | 6 | 0 | 1 | 148 | 52 | 96 | 2 | 26 | 
| Skerries | 7 | 5 | 0 | 2 | 203 | 88 | 115 | 5 | 25 | 
| Boyne | 7 | 5 | 0 | 2 | 134 | 98 | 36 | 2 | 22 | 
| Dundalk | 7 | 5 | 0 | 2 | 121 | 87 | 34 | 2 | 22 | 
| Cill Dara | 7 | 4 | 1 | 2 | 196 | 85 | 4 | 22 | |
| Tullamore | 7 | 4 | 0 | 3 | 152 | 72 | 80 | 4 | 20 | 
| Portlaoise | 6 | 2 | 0 | 4 | 106 | 109 | −3 | 4 | 12 | 
| Garda | 7 | 2 | 0 | 5 | 71 | 171 | −101 | 0 | 8 | 
| Tullow | 7 | 1 | 1 | 5 | 76 | 160 | −84 | 2 | 8 | 
| Enniscorthy | 6 | 0 | 0 | 6 | 83 | 158 | −75 | 3 | 3 | 
| Newbridge | 7 | 0 | 0 | 7 | 71 | 238 | −167 | 1 | 1 | 
| Wicklow | 7 | 0 | 0 | 7 | 31 | 305 | −274 | 1 | 1 | 
| Correct as of 19 November 2008 | |||||||||
2007/2008 Season
- Ashbourne
 - Boyne
 - Cill Dara
 - Dundalk
 - Garda
 - Monkstown
 - Navan
 - Portlaoise
 - Seapoint
 - Skerries
 - Tullamore
 - Wicklow
 
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.
2007/2008 Table
| 2008-2009 Leinster League Division One League Table | |||||||||
| Club | Played | Won | Drawn | Lost | Points for | Points against | Points difference | Bonus Points | Points | 
|---|---|---|---|---|---|---|---|---|---|
| Cill Dara | 11 | 10 | 1 | 0 | 279 | 183 | 96 | 4 | 46 | 
| Seapoint | 11 | 9 | 2 | 0 | 329 | 97 | 232 | 4 | 44 | 
| Navan | 11 | 8 | 1 | 2 | 247 | 111 | 136 | 4 | 38 | 
| Tullamore | 11 | 6 | 1 | 4 | 202 | 177 | 25 | 3 | 29 | 
| Dundalk | 11 | 5 | 0 | 6 | 186 | 164 | 26 | 5 | 25 | 
| Portlaoise | 11 | 4 | 1 | 6 | 184 | 248 | −64 | 5 | 23 | 
| Monkstown | 11 | 4 | 1 | 6 | 136 | 221 | −85 | 2 | 20 | 
| Boyne | 11 | 4 | 0 | 7 | 175 | 255 | −80 | 4 | 20 | 
| Garda | 11 | 4 | 1 | 6 | 163 | 230 | −67 | 1 | 19 | 
| Skerries | 11 | 3 | 0 | 8 | 127 | 170 | −43 | 5 | 17 | 
| Wicklow | 11 | 3 | 1 | 7 | 121 | 223 | −102 | 3 | 17 | 
| Ashbourne | 11 | 1 | 1 | 9 | 110 | 180 | −70 | 4 | 10 | 
| Correct as of 3 March 2008 | |||||||||
2006/2007 Season
- Boyne
 - Cill Dara
 - Dundalk
 - Enniscorthy
 - Garda
 - Kilkenny
 - Monkstown
 - Mullingar
 - Naas
 - Navan
 - Portlaoise
 - Seapoint
 - Skerries
 - Tullamore
 
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.
2006/2007 Table
| 2006-2007 Leinster League Division One League Table | |||||||||
| Club | Played | Won | Drawn | Lost | Points for | Points against | Points difference | Bonus Points | Points | 
|---|---|---|---|---|---|---|---|---|---|
| Naas | 13 | 12 | 0 | 1 | 364 | 141 | 223 | 9 | 57 | 
| Seapoint | 13 | 10 | 0 | 3 | 335 | 156 | 179 | 8 | 48 | 
| Navan | 13 | 10 | 0 | 3 | 357 | 266 | 91 | 7 | 47 | 
| Tullamore | 13 | 8 | 1 | 4 | 209 | 206 | 3 | 3 | 37 | 
| Boyne | 13 | 7 | 1 | 5 | 238 | 207 | 31 | 5 | 35 | 
| Cill Dara | 13 | 7 | 0 | 6 | 187 | 194 | −7 | 5 | 33 | 
| Skerries | 13 | 6 | 0 | 7 | 191 | 286 | −95 | 5 | 29 | 
| Garda | 13 | 5 | 0 | 8 | 191 | 215 | −24 | 5 | 25 | 
| Portlaoise | 13 | 4 | 1 | 8 | 184 | 196 | −12 | 6 | 24 | 
| Monkstown | 13 | 4 | 0 | 9 | 220 | 228 | −8 | 7 | 23 | 
| Dundalk | 13 | 4 | 0 | 9 | 215 | 234 | −19 | 6 | 22 | 
| Mullingar | 13 | 5 | 0 | 8 | 189 | 326 | −137 | −1 | 19 | 
| Enniscorthy | 13 | 4 | 0 | 9 | 154 | 243 | −89 | 3 | 19 | 
| Kilkenny | 13 | 3 | 1 | 9 | 129 | 165 | −136 | 1 | 15 | 
| Correct as of 21 November 2007 | |||||||||
Past winners
- 1994/1995 Dundalk
 - 1995/1996 Suttonians
 - 1996/1997 Co Carlow
 - 1997/1998 Naas
 - 1998/1999 Barnhall
 - 1999/2000 Naas
 - 2000/2001 Navan
 - 2001/2002 Kilkenny
 - 2002/2003 Kilkenny
 - 2003/2004 Seapoint RFC
 - 2004/2005 Naas
 - 2005/2006 Monkstown
 - 2006/2007 Naas
 - 2007/2008 Cill Dara
 - 2008/2009 Navan
 - 2009/2010 Seapoint RFC
 
Wins by club
- Naas (4 times)
 - Kilkenny (twice)
 - Navan (Twice)
 - Seapoint RFC (Twice)
 - Barnhall (once)
 - Cill Dara (once)
 - Co Carlow (once)
 - Dundalk (once)
 - Monkstown (once)
 - Suttonians (once)