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

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

World record	Michael Phelps (USA)	4:03.84	Beijing, China	10 August 2008
Pan Pacific Championships record	Ryan Lochte (USA)	4:07.59	Irvine, United States	19 August 2010

All times are in minutes and seconds.

Heats

The first round was held on 9 August from 10:00.^[3]

Only two swimmers from each country may advance to the A or B final. If a country not qualify any swimmer to the A final, that same country may qualify up to three swimmers to the B final.^[4]

Rank	Name	Nationality	Time	Notes
1	Chase Kalisz	United States	4:10.97	QA
2	Daiya Seto	Japan	4:12.49	QA
3	Kosuke Hagino	Japan	4:12.65	QA
4	Jay Litherland	United States	4:13.00	QA
5	Sean Grieshop	United States	4:14.27	QB
6	Brandonn Almeida	Brazil	4:15.71	QA
7	Lewis Clareburt	New Zealand	4:17.93	QA
8	Hiromasa Fujimori	Japan	4:20.01	QB
9	Leonardo Santos	Brazil	4:21.60	QA
9	Tristan Cote	Canada	4:21.60	QA
11	Deng Ziqi	China	4:31.88	QB

B Final

The B final was held on 9 August from 17:30.^[5]

Rank	Name	Nationality	Time	Notes
9	Sean Grieshop	United States	4:14.33
10	Hiromasa Fujimori	Japan	4:22.55
11	Deng Ziqi	China	4:27.76

A Final

The A final was held on 9 August from 17:30.^[6]

Rank	Name	Nationality	Time	Notes
	Chase Kalisz	United States	4:07.95
	Kosuke Hagino	Japan	4:11.13
	Daiya Seto	Japan	4:12.60
4	Jay Litherland	United States	4:12.87
5	Lewis Clareburt	New Zealand	4:14.27	NR
6	Brandonn Almeida	Brazil	4:14.53
7	Leonardo Santos	Brazil	4:18.90
8	Tristan Cote	Canada	4:21.72