| Placing | Athlete | Team | Preliminaries |
|---|---|---|---|
| 1 | Ollie Singleton | Christchurch Boys High School | 52.79q |
| 2 | Will McMeeken | Christchurch Boys High School | 53.32q |
| 3 | Millar McElrea | John McGlashan College | 53.49q |
| 4 | Liam O'Riordan-Lawlor | South Otago High School | 55.99 |
| 5 | Oscar Stevenson | Darfield High School | 56.87 |
| Placing | Athlete | Team | Preliminaries |
|---|---|---|---|
| 1 | Cody Armstrong | Mt Aspiring College | 52.78q |
| 2 | Sakun Balasuriya | Nelson College | 53.97q |
| 3 | Ted Ward | Rolleston College | 54.50q |
| 4 | Caleb Diprose | Aparima College | 54.64q |
| 5 | Louis Pienaar | James Hargest College | 55.66q |
| 6 | Ivan Temple | Fiordland College | 1:00.29 |
| Placing | Athlete | Team | Finals |
|---|---|---|---|
| 1 | Ollie Singleton | Christchurch Boys High School | 51.64 |
| 2 | Millar McElrea | John McGlashan College | 52.29 |
| 3 | Cody Armstrong | Mt Aspiring College | 52.61 |
| 4 | Will McMeeken | Christchurch Boys High School | 53.65 |
| 5 | Sakun Balasuriya | Nelson College | 53.77 |
| 6 | Ted Ward | Rolleston College | 54.30 |
| 7 | Caleb Diprose | Aparima College | 55.16 |
| 8 | Louis Pienaar | James Hargest College | 57.56 |