| 16 years |
| Aust Age: | 48.05 | *Flynn Southham (Bond, QLD) | 17 Sep 2021 |
| Age AllComer: | 48.05 | *Flynn Southham (Bond, QLD) | 17 Sep 2021 |
| WA All Comer: | 49.05 | Ian Thorpe (SLC Aquadot, NSW) | 27 Sep 1998 |
| WA All Time: | 49.89 | Kalani Ireland (St Hilda's, WA) | 26 Aug 2018 |
| WA Resident: | 49.89 | Kalani Ireland (St Hilda's, WA) | 26 Aug 2018 |
|
| # | Name | Age | School | Entry | Result | | Points |
| 1st | Ryan, Lucas | 16 | Hale Aquatics | 53.52 | 51.40 | -2.12s | 10 |
| 2nd | Yoong, Boston | 16 | Southside Penrhos Wesley Swimm | 51.97 | 51.83 | -0.14s | 8 |
| 3rd | Smith, Tadhg | 16 | Hale Aquatics | 52.54 | 52.65 | +0.11s | 6 |
| 4th | Al Naser, Ali | 16 | Riverton Aquanauts Incorporate | 53.82 | 52.88 | -0.94s | 5 |
| 5th | Williams, Sheldon | 16 | Breakers WA | 57.66 | 52.92 | -4.74s | 4 |
| 6th | Powell, Joshua | 16 | Hale Aquatics | 53.82 | 52.95 | -0.87s | 3 |
| 7th | Spencer, Charlie | 16 | Westside Christ Church Aquatic | 52.00 | 53.03 | +1.03s | 2 |
| 8th | Whyte, Jesse | 16 | Breakers WA | 54.05 | 53.88 | -0.17s | 1 |
| 9th | O'Sullivan, Zach | 16 | UWA-West Coast Swimming Club | 55.62 | 54.54 | -1.08s | |
| 10th | van Waas, Tristan | 16 | Rockingham Swimming Club | 56.23 | 54.61 | -1.62s | |
| 11th | Kryachok, Nicholas | 16 | Hale Aquatics | 57.42 | 54.88 | -2.54s | |
| 12th | Cartmell, Caiden | 16 | Breakers WA | 54.89 | 55.00 | +0.11s | |
| 13th | May, Hudson | 16 | Western Sprint Swimming Club | 54.07 | 55.22 | +1.15s | |
| 14th | Jocson, Laurence Kyle | 16 | Australind Swimming Club | 55.43 | 55.59 | +0.16s | |
| 15th | Warrilow, John | 16 | South Shore | 56.24 | 55.68 | -0.56s | |
| 16th | McDonough, Luke | 16 | Mandurah Swimming Club | 56.09 | 55.94 | -0.15s | |
| 17th | Brown-Neaves, Callum | 16 | Celts Swimming Club | 55.80 | 56.10 | +0.30s | |
| 18th | Hughes, Toby | 16 | Rockingham Swimming Club | 56.24 | 56.11 | -0.13s | |
| 19th | Barros, Danilo | 16 | South Lake Dolphins | 56.31 | 56.26 | -0.05s | |
| 19th | Dwyer, Nikolay | 16 | Westside Christ Church Aquatic | 55.48 | 56.26 | +0.78s | |
| 21st | Strahan, Noah | 16 | Riverton Aquanauts Incorporate | 57.08 | 56.39 | -0.69s | |
| 22nd | Talbot, James | 16 | Westside Christ Church Aquatic | 57.95 | 56.86 | -1.09s | |
| 23rd | O'Toole, Tighe | 16 | UWA-West Coast Swimming Club | 57.58 | 57.29 | -0.29s | |
| 24th | Watson, Christian | 16 | South Shore | 58.55 | 57.50 | -1.05s | |
| 25th | Colman, Jeremy | 16 | UWA-West Coast Swimming Club | 56.11 | 57.57 | +1.46s | |
| 26th | Collins, Hugo | 16 | Newman Churchlands | 58.62 | 58.47 | -0.15s | |
| 27th | Megebry, Youssef | 16 | UWA-West Coast Swimming Club | 58.62 | 58.56 | -0.06s | |
| 17 years |
| Aust Age: | 47.04 | *Flynn Southham (Australia) | 13 Dec 2022 |
| Age AllComer: | 47.04 | *Flynn Southham (Australia) | 13 Dec 2022 |
| WA All Comer: | 48.30 | Alexander Graham (SKC, VIC) | 15 Sep 2012 |
| WA All Time: | 48.27 | Tommaso D'Orsogna (West Coast, WA) | 24 Sep 2008 |
| WA Resident: | 49.28 | Joshua Edwards-Smith (UWA West Coast) | 5 Sep 2020 |
|
| # | Name | Age | School | Entry | Result | | Points |
| 1st | Carmignani, Sam | 17 | Hale Aquatics | 50.75 | 50.30 | -0.45s | 10 |
| 2nd | Fackerell, Lucas | 17 | Hale Aquatics | 50.49 | 50.41 | -0.08s | 8 |
| 3rd | Szczecinski, Griffin | 17 | Southside Penrhos Wesley Swimm | 54.41 | 51.86 | -2.55s | 6 |
| 4th | Wilson, Jurgens | 17 | Westside Christ Church Aquatic | 53.82 | 52.03 | -1.79s | 5 |
| 5th | Zver, Romeo | 17 | Rockingham Swimming Club | 54.21 | 52.37 | -1.84s | 4 |
| 6th | O'Beirne, Archie | 17 | Busselton Swimming Club | 53.68 | 52.96 | -0.72s | 3 |
| 7th | Beardmore, Thomas | 17 | Riverton Aquanauts Incorporate | 53.98 | 53.29 | -0.69s | 2 |
| 8th | Ashby, Jack | 17 | Highlanders | 53.95 | 53.42 | -0.53s | 1 |
| 9th | Bromwell, Fletcher | 17 | Highlanders | 54.36 | 53.44 | -0.92s | |
| 10th | McMahon, Caleb | 17 | Newman Churchlands | 55.93 | 53.59 | -2.34s | |
| 11th | Foster, Jake | 17 | UWA-West Coast Swimming Club | 52.65 | 53.77 | +1.12s | |
| 12th | Penegar, Lochlan | 17 | Westside Christ Church Aquatic | 54.45 | 54.31 | -0.14s | |
| 13th | Dickie, Jack | 17 | City of Perth Swimming Club | 55.53 | 54.56 | -0.97s | |
| 14th | Palenberg, Keno | 17 | South Lake Dolphins | 56.89 | 55.56 | -1.33s | |
| 15th | Carroll, Felix | 17 | Broome Barracudas | 58.51 | 56.88 | -1.63s | |
| 16th | Bradbrook, Bailey | 17 | Hale Aquatics | 56.14 | 57.05 | +0.91s | |
| 17th | Woodage, Noah | 17 | Mandurah Swimming Club | 59.01 | 58.02 | -0.99s | |
| 18th | Janssens, Austin | 17 | UWA-West Coast Swimming Club | 59.21 | 58.47 | -0.74s | |
| 19th | Palmer, Jasper | 17 | Armadale Kelmscott | 55.53 | 59.14 | +3.61s | |
| Duan, Anyi | 17 | Riverton Aquanauts Incorporate | 56.58 | NS | | |