| 1 | Brinley Horras JR | Ames | 5:00.93 | Ames High School | 09/18/2018 |
| 2 | Aurora Roghair SO | Iowa City, West | 5:02.43 | Linn-Mar Aquatic Center | 10/13/2018 |
| 3 | Clare Culver SR | Dowling Catholic | 5:04.15 | Trail Point Aquatics & Wellness | 09/25/2018 |
| 4 | Berit Quass JR | Dowling Catholic | 5:04.86 | Linn-Mar High School | 09/08/2018 |
| 5 | Libby Staver SR | Pleasant Valley | 5:06.97 | Linn-Mar High School | 09/08/2018 |
| 6 | Meg Susil SO | Dowling Catholic | 5:07.68 | Ames High School | 10/10/2018 |
| 7 | Katie Broderick JR | Dowling Catholic | 5:09.95 | Valley High School | 09/22/2018 |
| 8 | Scarlet Martin FR | Iowa City, West | 5:11.53 | Coralville Recreation Center | 09/04/2018 |
| 9 | Erin Doruska SR | Ankeny | 5:12.41 | Trail Point Aquatics & Wellness | 09/11/2018 |
| 10 | Grace Considine SR | Cedar Falls | 5:14.15 | Cedar Falls High School | 09/29/2018 |
| 11 | Anna Hamling JR | Waukee | 5:15.73 | Waukee Family YMCA | 10/09/2018 |
| 12 | Maggie Eure JR | Dowling Catholic | 5:16.10 | Summit Middle School | 10/18/2018 |
| 13 | Abby Hala FR | Ames | 5:17.44 | Summit Middle School | 09/25/2018 |
| 14 | Madison Carleton FR | Ankeny | 5:17.58 | Trail Point Aquatics & Wellness | 09/25/2018 |
| 15 | Mary Sweetman SO | Dowling Catholic | 5:18.27 | Fort Dodge Senior High School | 09/15/2018 |
| 16 | Clare Sweetman SR | Dowling Catholic | 5:18.58 | Trail Point Aquatics & Wellness | 09/25/2018 |
| 17 | | Cedar Rapids, Washington | 5:19.46 | Washington High School | 09/11/2018 |
| 18 | Lydia Johnston SO | Des Moines, Roosevelt | 5:19.72 | Trail Point Aquatics & Wellness | 09/11/2018 |