400m SEN Women, Heat:1 of 3 ; Official result since 19:40
Joanne Cuddihy 50.73
| Rank | Lane | ID | Name | PB | Team | Cat | Result | Info | Video |
| 1 | 4 | 523 | MOONEY Claire | Naas A.C. | 55.12 | Q | |||
| 2 | 5 | 124 | SCALLAN Susan | Raheny Shamrock A.C. | 55.21 | Q | |||
| 3 | 6 | 94 | COVENEY Gabrielle | Dundrum A.C. | 56.50 | q | |||
| 4 | 7 | 325 | O'TOOLE Ellie | Newbridge A.C. | 58.72 | ||||
| 5 | 2 | 419 | GRACE Margaret Mary | Nenagh Olympic A.C. | 1:03.28 | ||||
| 6 | 3 | 141 | BOWE Ruth | Menapians A.C. | 1:05.77 |