| Name | Last Run |
|---|---|
| Oppidum | Palermo, 09-Oct-23 |
| Oppo Taco | Charles Town, 17-May-24 |
| Opportun | Saint-Cloud, 13-Jun-25 |
| Opportune Chance | Gawler, 28-May-25 |
| Opportune Notion | Delaware Park, 24-Jul-25 |
| Opportune Notion | Delaware Park, 16-Oct-25 |
| Opportunistic | Ascot, 25-Oct-25 |
| Opportunities Won | Kalgoorlie, 09-Jun-13 |
| Opportunity Knocks | Chelmsford City, 20-Oct-23 |
| Opportunity Lost | Sportsbet-Wangaratta, 20-Aug-22 |
| Opportunity Set | Belmont At The Big A, 23-Jun-24 |
| Oppose | Colonial Downs, 28-Aug-25 |
| Opposing | Moe, 04-Jun-23 |
| Opposite Ends | Limerick, 20-Oct-24 |
| Opposite The Crowd | Delaware Park, 18-Jul-25 |
| Opposites Attract | Gulfstream, 27-Jun-25 |
| Opposition | Caulfield, 17-Oct-18 |
| Oppressiveness | Wagga, 17-Sep-22 |
| Oppy | Horseshoe Indianapolis, 23-Oct-25 |
| Oprah | Mackay, 19-Oct-14 |
| Opry | Mountaineer, 09-Oct-25 |
| OPSHOP | Ipswich, 28-Oct-11 |
| OPTER | Warwick Farm, 17-Feb-10 |
| Optic View | Stony Creek, 08-Jan-18 |
| Optic Way | Monmouth Park, 09-Jun-25 |
| Optical | Churchill Downs, 29-Sep-25 |
| Optical Bijou | Laurel Park, 27-Oct-25 |
| Optical Illusion | Los Alamitos Racecourse, 13-Oct-25 |
| Opticality | Worcester, 18-Jun-25 |
| Optician | Lingfield, 18-Apr-25 |
| Optics | Listowel, 23-Sep-25 |
| Optics | Mizusawa, 05-Oct-25 |
| Optik | Chelmsford City, 07-Apr-24 |
| OPTIMAL | Mornington, 13-Jun-11 |
| Optimal | Albany, 02-Nov-25 |
| Optimal | Fonner Park, 12-Apr-25 |
| Optimal Courage | Canterbury Park, 02-Jun-25 |
| Optimal Moments | Mornington, 19-Apr-25 |
| Optimal Sinn | Lingfield, 13-Dec-23 |
| Optimal Trip | Lone Star, 04-May-25 |
| Optimatum | Nottingham, 07-Aug-25 |
| Optimise Prime | Uttoxeter, 19-Mar-23 |
| Optimistic | Wolverhampton, 29-Oct-25 |
| Optimistic Belief | Kempton, 11-Feb-23 |
| Optimistic Cowgirl | Lone Star, 06-Jul-25 |
| Optimistic Income | Horseshoe Indianapolis, 07-Aug-25 |
| Optimistic Joe | Worcester, 01-Jun-24 |
| Optimistic Nate | Charles Town, 06-Nov-25 |
| Optimistic Valor | Assiniboia Downs, 25-Sep-24 |
| Optimistic Woman | Will Rogers Downs, 23-Apr-24 |
| Optimize | Gawler, 26-Oct-18 |
| Optimizme | Mahoning Valley, 04-Jan-24 |
| Optimizzer | Lismore, 21-Sep-23 |
| Optimo | Adaminaby, 18-Nov-23 |
| Optimus | Dieppe, 01-Sep-25 |
| Optimus Kat | Remington Park, 17-Oct-25 |
| Optimus King | San Isidro, 01-Feb-24 |
| Optimus Maximus | Bundaberg, 26-Jul-25 |
| Option | Fairmount Park, 25-Oct-23 |
| Option Plan | Mombetsu, 06-Nov-24 |