2018 Pan Pacific Swimming Championships – Women's 400 metre individual medley
# 2018 Pan Pacific Swimming Championships – Women's 400 metre individual medley

The women's 400 metre individual medley competition at the 2018 Pan Pacific Swimming Championships took place on August 9 at the Tokyo Tatsumi International Swimming Center. The defending champion was Elizabeth Beisel of the United States.

## Records

Prior to this competition, the existing world and Pan Pacific records were as follows:

| World record | Katinka Hosszú (HUN) | 4:26.36 | Rio de Janeiro, Brazil | 6 August 2016 |
| - | - | - | - | - |
| Pan Pacific Championships record | Elizabeth Beisel (USA) | 4:31.99 | Gold Coast, Australia | 22 August 2014 |

## Results

All times are in minutes and seconds.

| KEY: | QA | Qualified A Final | QB | Qualified B Final | CR | Championships record | NR | National record | PB | Personal best | SB | Seasonal best |
| - | - | - | - | - | - | - | - | - | - | - | - | - |

### Heats

The first round was held on 9 August from 10:00.

Only two swimmers from each country may advance to the A or B final. If a country does not qualify any swimmer to the A final, that same country may qualify up to three swimmers to the B final.

| Rank | Name | Nationality | Time | Notes |
| - | - | - | - | - |
| 1 | Yui Ohashi | Japan | 4:36.05 | QA |
| 2 | Melanie Margalis | United States | 4:39.09 | QA |
| 3 | Sakiko Shimizu | Japan | 4:39.76 | QA |
| 4 | Emily Overholt | Canada | 4:40.63 | QA |
| 5 | Brooke Forde | United States | 4:40.76 | QA |
| 6 | Allyson McHugh | United States | 4:41.08 | QB |
| 7 | Erika Seltenreich-Hodgson | Canada | 4:44.64 | QA |
| 8 | Ye Huiyan | China | 4:57.65 | QA |
| 9 | Chloe Isleta | Philippines | 4:59.21 | QA |
| 10 | Gianna Garcia | Philippines | 5:28.80 | QB |

### B Final

The B final was held on 9 August from 17:30.

| Rank | Name | Nationality | Time | Notes |
| - | - | - | - | - |
| 9 | Allyson McHugh | United States | 4:41.04 | |
| 10 | Gianna Garcia | Philippines | 5:27.19 | |

### A Final

The A final was held on 9 August from 17:30.

| Rank | Name | Nationality | Time |
| - | - | - | - |
| | Yui Ohashi | Japan | 4:33.77 |
| | Melanie Margalis | United States | 4:35.60 |
| | Sakiko Shimizu | Japan | 4:36.27 |
| 4 | Brooke Forde | United States | 4:39.22 |
| 5 | Emily Overholt | Canada | 4:39.48 |
| 6 | Erika Seltenreich-Hodgson | Canada | 4:40.22 |
| 7 | Ye Huiyan | China | 4:52.40 |
| 8 | Chloe Isleta | Philippines | 4:58.81 |
