Start Time: 02:15pm
WR 47.60 Marita Koch (GDR)
ER 47.60 Marita Koch (GDR)
IR 50.73 Joanne Cuddihy (IRL)
MR 50.81 Olga Bryzgina (RUS)
| Place | No. | Lane | Name | Country | YOB | Official Time | Reaction Time |
| 1 | 100 | 7 | Claire Mooney | Ireland | 56.48 | ||
| 2 | 155 | 4 | Louise McArdle | Ireland | 57.17 | 0,230 | |
| 3 | 121 | 5 | Ciara Everard | Ireland | 90 | 57.79 | 0,244 |
| 4 | 183 | 3 | Susan Scanlon | Ireland | 57.86 | 0,264 | |
| 5 | 184 | 2 | Emer O’Connell | Ireland | 57.93 | 0,221 | |
| 6 | 115 | 6 | Kalyn Sheehan | Ireland | 89 | 58.26 | |
| 7 | 178 | 1 | Kate Humphries | Ireland | 59.58 | ||
| DNS | 185 | 8 | Jessica Zebo | Ireland | 84 | DNS |
