400m Jun Men, Heat:1 of 3 ; Official result since 12:23
| Rank | Lane | ID | Name | PB | Team | Cat | Result | Info | Video |
| 1 | 5 | 224 | LOCKE Cathal | Dooneen A.C. | 50.58 | Q | |||
| 2 | 3 | 185 | CLANCY Diarmuid | Abbey Striders A.C. | 51.43 | ||||
| 3 | 6 | 6 | KEENAN Ryan | City of Lisburn AC | 52.99 | ||||
| 4 | 2 | 4 | MCCORRY Diarmuid | Annalee A.C. | 53.07 | ||||
| 5 | 1 | 364 | MCNABOLA Kyle | Carrick-on-Shannon A.C. | 53.65 | ||||
| 6 | 4 | 181 | HERITY Conor | North Sligo A.C. | 54.60 |