| Event | Time | Meet | Date |
|---|---|---|---|
| 100m Backstroke | 1:14.74 | Scar Pan Am Winter Classic | 2026-01-16 |
| 100m Backstroke | 1:10.51 | 2026 Central Region Div 1 SC Championships | 2026-02-06 |
| 100m Breaststroke | 1:35.02 | 2025 Central Region Div 2 LC Championships | 2025-06-13 |
| 100m Breaststroke | 1:24.94 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 100m Butterfly | 1:17.37 | 2025 Central Region Div 2 LC Championships | 2025-06-13 |
| 100m Butterfly | 1:13.96 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 100m Freestyle | 1:03.85 | MAC Summer Invitational | 2025-07-24 |
| 100m Freestyle | 1:01.65 | 2026 Central Region Div 1 SC Championships | 2026-02-06 |
| 200m Backstroke | 2:44.22 | 2025 Central Region Div 2 LC Championships | 2025-06-13 |
| 200m Backstroke | 2:35.40 | 2025 Age Group International SC | 2025-11-27 |
| 200m Breaststroke | 3:15.21 | 2025 Central Region Div 2 LC Championships | 2025-06-13 |
| 200m Breaststroke | 3:02.18 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 200m Freestyle | 2:20.07 | Scar Pan Am Winter Classic | 2026-01-16 |
| 200m Freestyle | 2:17.08 | 2026 Central Region Div 1 SC Championships | 2026-02-06 |
| 200m IM | 2:41.91 | Scar Pan Am Winter Classic | 2026-01-16 |
| 200m IM | 2:43.81 | Border City Invitational 2025 | 2025-12-05 |
| 400m Freestyle | 5:11.91 | 2025 Central Region Div 2 LC Championships | 2025-06-13 |
| 400m Freestyle | 5:05.17 | Border City Invitational 2025 | 2025-12-05 |
| 400m IM | 5:58.29 | MAC Summer Invitational | 2025-07-24 |
| 400m IM | 5:39.44 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 50m Backstroke | 34.96 | MAC Summer Invitational | 2025-07-24 |
| 50m Backstroke | 32.97 | Border City Invitational 2025 | 2025-12-05 |
| 50m Breaststroke | 40.26 | Scar Pan Am Winter Classic | 2026-01-16 |
| 50m Breaststroke | 38.21 | 2026 Central Region Div 2 SC Championships | 2026-02-20 |
| 50m Butterfly | 31.52 | 2025 Age Group International LC | 2025-06-05 |
| 50m Butterfly | 31.47 | 2025 Age Group International SC | 2025-11-27 |
| 50m Freestyle | 28.07 | 2026 MMST GTA Skins | 2026-02-13 |
| 50m Freestyle | 28.04 | 2026 Central Region Div 1 SC Championships | 2026-02-06 |
| 800m Freestyle | 10:12.00 | Border City Invitational 2025 | 2025-12-05 |
Muir, Cassidy's top personal bests include 100m Backstroke (1:14.74), 100m Backstroke (1:10.51), 100m Breaststroke (1:35.02), 100m Breaststroke (1:24.94), 100m Butterfly (1:17.37).
Muir, Cassidy swims for Oshawa Aquatic Club.
Muir, Cassidy has competed in 13 meets.