| 15 years |
| Aust Age: | 57.16 | *Minna Atherton (QLD) | 25 Nov 2015 |
| Age AllComer: | 57.16 | *Minna Atherton (QLD) | 25 Nov 2015 |
| WA All Comer: | 59.23 | Iona Anderson (Breakers, WA) | 21 Aug 2021 |
| WA All Time: | 59.23 | Iona Anderson (Breakers, WA) | 21 Aug 2021 |
| WA Resident: | 59.23 | Iona Anderson (Breakers, WA) | 21 Aug 2021 |
|
| # | Name | Age | School | Entry | Result | | Points |
| 1st | Dunbar, Mia | 15 | Southside Penrhos Wesley Swimm | 1:05.17 | 1:04.36 | -0.81s | 10 |
| 2nd | Wright, Lara | 15 | Breakers WA | 1:07.96 | 1:05.57 | -2.39s | 8 |
| 3rd | Campbell, Bronte | 15 | Highlanders | 1:08.95 | 1:09.12 | +0.17s | 6 |
| 4th | Sell, Lily | 15 | Breakers WA | 1:09.88 | 1:10.30 | +0.42s | 5 |
| 5th | Rayne, Brooklyn | 15 | Busselton Swimming Club | 1:07.59 | 1:10.48 | +2.89s | 4 |
| 6th | DiGiuseppe, Aria | 15 | Fenix Swim Club Inc. | 1:10.54 | 1:11.30 | +0.76s | 3 |
| 7th | Turner, Leni Sophie | 15 | Guildford & Kalamunda District | 1:14.29 | 1:12.30 | -1.99s | 2 |
| 8th | Wallace, Bridget | 15 | Riverton Aquanauts Incorporate | 1:13.25 | 1:12.88 | -0.37s | 1 |
| 9th | Chitaek, Cherry | 15 | Guildford & Kalamunda District | 1:15.23 | 1:13.83 | -1.40s | |
| 10th | Smit, Eleanor | 15 | Armadale Kelmscott | 1:13.10 | 1:14.29 | +1.19s | |
| 11th | Duncan, Stella | 15 | Westside Christ Church Aquatic | 1:14.25 | 1:14.79 | +0.54s | |
| 12th | Higgins, Jemma | 15 | North Coast Swim Club | 1:13.68 | 1:15.64 | +1.96s | |
| Riddell, Sophia | 15 | Albany Swimming Club Inc | 1:15.16 | 1:17.35 | +2.19s | |
| 16 years |
| Aust Age: | 56.76 | *Mollie O'Callaghan (QLD) | 26 Nov 2020 |
| Age AllComer: | 56.76 | *Mollie O'Callaghan (QLD) | 26 Nov 2020 |
| WA All Comer: | 59.23 | Iona Anderson (Breakers, WA) | 21 Aug 2021 |
| WA All Time: | 59.23 | Iona Anderson (Breakers, WA) | 21 Aug 2021 |
| WA Resident: | 59.23 | Iona Anderson (Breakers, WA) | 21 Aug 2021 |
|
| # | Name | Age | School | Entry | Result | | Points |
| 1st | Milne, Eilidh | 16 | Celts Swimming Club | 1:05.75 | 1:06.57 | +0.82s | 10 |
| 2nd | Malone, Aoife | 16 | Breakers WA | 1:10.26 | 1:08.00 | -2.26s | 8 |
| 3rd | Pitt, Sienna | 16 | South Lake Dolphins | 1:10.82 | 1:08.69 | -2.13s | 6 |
| 4th | Maley, Megan | 16 | Mandurah Swimming Club | 1:08.25 | 1:08.77 | +0.52s | 5 |
| 5th | Lund, Eleanor | 16 | South Shore | 1:09.72 | 1:11.58 | +1.86s | 4 |
| 6th | Elliott, Georgia | 16 | Fenix Swim Club Inc. | 1:11.53 | 1:12.04 | +0.51s | 3 |
| 7th | Greenwell-Roberts, Amy | 16 | South Lake Dolphins | 1:10.59 | 1:13.01 | +2.42s | 2 |