| Equid | Horse Name ▲ | Breed | Age | Gender | Color | Discipline | Owner |
|---|---|---|---|---|---|---|---|
| 087017S | Ocupada | Andalusian | SY17 (11yo) | Mare | Grey | HU | Jewel |
| 516126B | Odd Man Out | Quarter Horse | SY26 (2yo) | Stallion | Bay Dun | SR | Rhianon |
| 396719C | Oddfellow | Holsteiner | SY18 (10yo) | Stallion | Grey | JP | Faline |
| 082817S | Odyssey | Losino Pony | SY17 (11yo) | Stallion | Black | WE | Lissa |
| 379418C | Odzhar | Akhal Teke | SY18 (10yo) | Stallion | Bay Dun | EN | Niamh |
| 176511C | Off The Deep End | Appaloosa | SY11 (17yo) | Mare | Buckskin Roan Blanket | WS | Lissa |
| 487527B | Offended Prince | Thoroughbred | SY27 (1yo) | Stallion | Chestnut | FR | Morrigan |
| 525228B | Oh Shoot Man CR | Quarter Horse | SY28 (0yo) | Stallion | Bay | WR | Morrigan |
| 409523B | OhNoShezaWitch CCR | Paint Horse | SY23 (5yo) | Mare | Buckskin Overo | WW | Morrigan |
| 150513C | Oklahoma | Thoroughbred | SY13 (15yo) | Mare | Chestnut | EN | Lissa |
| 268522B | Oklahoma Red | Thoroughbred | SY22 (6yo) | Mare | Chestnut Overo Sabino | FR | Lissa |
| 468023B | Oktovris | Irish Sport Horse | SY23 (5yo) | Stallion | Palomino White-Spotted | EV | Rhianon |
| 219115C | Olive Branch | Noriker | SY15 (13yo) | Mare | Bay Leopard | DV | Jen |
| 028111B | Olympia | Friesian | SY11 (17yo) | Mare | Black | DG | Lissa |
| 241522C | OmegaMart | Paint Horse | SY22 (6yo) | Mare | Blue Roan Overo | WS | Morrigan |
| 526828B | OMG Johnny What CR | Quarter Horse | SY28 (0yo) | Stallion | Palomino | SR | Morrigan |
| 259418B | Ominous Haze | Connemara | SY18 (10yo) | Mare | Grey | CC | Lissa |
| 251018C | On A Whimsy | Welsh Pony | SY18 (10yo) | Mare | Bay | JP | Soleil |
| 260621B | On Impact | Hackney Pony | SY21 (7yo) | Mare | Bay | DV | Lissa |
| 059414S | On The Brink | Iberian Warmblood | SY14 (14yo) | Stallion | Bay Dun Blanket | WE | Jen |
| 398520B | On The Dot CCR | Appaloosa | SY20 (8yo) | Stallion | Bay Snowcap | WW | Merry |
| 067121S | On The Rox | Thoroughbred | SY21 (7yo) | Mare | Black | FR | Jewel |
| 236322B | Once Jurassic | Appaloosa | SY22 (6yo) | Mare | Red Dun Leopard | SR | Lissa |
| 251117C | Once Upon A December | Holsteiner | SY17 (11yo) | Mare | Bay | JP | The Orchard |
| 488327B | One Black Coffee | Thoroughbred | SY27 (1yo) | Mare | Grey | FR | Morrigan |
