| Registered Name | Owner / Club | Status |
|---|---|---|
| Out of Orbit | Janet O' Byrne Hollybrook | Approved |
| Out Of The Blue | Helen Clarke Ashbrook | Approved |
| Outrun Your Brother | Sophie De Jong Fingal | Approved |
| Overdraught Hero | Gemma O' Sullivan Horetown | Approved |
| Overhaven Sinatra | Jean Robertson Mo Chara | Approved |
| Overton Boy | Amelia Paulsen Tynagh | Approved |
| Ovidstown Ben | Joe Conway Golden Grove | Approved |
| Owenbuoy Blue Ruben | Joanne McCarthney Letterkenny | Approved |
| Owens Boy | Cathriona Goaley Springmount | Approved |
| Ower April Lady | Fidelma Mc Hugh South Roscommon | Approved |
| OWT Christian G | Sarah Duffy Ashbrook | Approved |
| Ox View Ali | Jenny Jakeman Springmount | Approved |
| Ox View Paddy | Lizzy Naughton Round Tower | Approved |
| Oxmountain Heather | Maria Morgan Lakelands | Approved |
| Oxview Jasper | Lizzy Naughton Round Tower | Approved |