| UNSHUSHABLE | |
| Unsimilar | Saga,
09-Mar-25 |
| Unsinkable | Kanazawa,
14-Nov-23 |
| Unsinkable Molly B | Carlisle,
17-Dec-23 |
| Unsinkable Sam | Newcastle,
26-Dec-17 |
| Unskinny Bob | Penola,
20-Apr-25 |
| Unsnoozual | Mornington,
23-Oct-25 |
| Unsociable | Turfway Park,
28-Mar-25 |
| Unsolved | Coonamble,
12-Oct-25 |
| Unsolved | Gawler,
28-Dec-11 |
| Unsolved Mystery | Monmouth Park,
15-Sep-25 |
| Unsolved Riddle | Vaal,
23-Oct-25 |
| Unspeakable | Exeter,
21-Oct-25 |
| Unspoken | Grafton,
02-Oct-15 |
| Unspoken | Eagle Farm,
14-Jun-25 |
| Unspoken Love | Curragh,
15-Sep-24 |
| Unspoken Request | Gulfstream,
24-May-25 |
| Unspoken Star | Cootamundra,
18-May-24 |
| Unstable Prince | Ellis Park,
09-Aug-25 |
| Unstable Princess | Presque Isle Downs,
18-Jul-24 |
| Unstable Storm | Fort Erie,
12-Aug-24 |
| Unstopabull | Canterbury,
06-Aug-25 |
| Unstoppable | Wincanton,
07-Jan-23 |
| Unstoppable | Ohi,
13-Aug-24 |
| Unstoppable | Monterrico,
31-Jul-23 |
| Unstoppable Appeal | Gulfstream,
27-May-23 |
| Unstoppable Force | Canterbury Park,
31-Jul-23 |
| Unstoppable Me | Turf Paradise,
02-May-23 |
| Unsubscribe | Bunbury,
27-Feb-25 |
| Unsung Hero | Kempton,
11-Jul-24 |
| Unsung Hero | Nagoya,
22-Aug-25 |
| Unsung Hero | Kenilworth,
05-Nov-24 |
| Unsung Heroine | Mizusawa,
16-Sep-25 |
| UNSUNG HEROINE | Newmarket (GB),
18-Oct-08 |
| Unsung Melody | Keeneland,
14-Oct-24 |
| Unsure | Gladstone,
25-Sep-21 |
| Unsure Miss | TRIAL Aquis Park Gold Coast,
20-May-25 |
| Unsurpassed | Kanazawa,
23-Jul-24 |
| Unsustainable | Golden State Racing,
24-Nov-24 |
| Unswayed | Philadelphia Park,
15-Apr-25 |
| UNSWEPT | Ipswich,
16-Jul-10 |
| Unswerving | |
| Untameable | Gosford,
09-Jun-11 |
| UNTAMED | Queanbeyan,
29-Jun-09 |
| UNTAMED HARMONY | |
| Untamed Mistress | Port Macquarie,
01-Jan-23 |
| Untamed Moment | Ellis Park,
17-Aug-25 |
| Untamed Shrew | Gulfstream,
30-Aug-25 |
| Untamed Spirit | Tabulam,
05-Oct-24 |
| Untapable | Pinjarra Park,
18-Aug-16 |
| Untapped | Flemington,
17-May-25 |
| Untapped Energy | Mahoning Valley,
03-Jan-23 |
| Untapped Potential | TRIAL Scone,
31-Aug-22 |
| Untempted | Will Rogers Downs,
30-Sep-25 |
| Unterberg | Leopardstown,
22-Aug-25 |
| Unterhaltsam | |
| UNTERHALTUNG | |
| Untethered | Bendigo,
07-Sep-25 |
| Unthinkable | Redcar,
04-Nov-25 |
| Unthinkable | Mt Gambier,
21-Mar-25 |