| Men's 400 metre freestyle at the 2025 SEA Games | |
|---|---|
| Venue | SAT Swimming Pool |
| Date | 15 December |
| Competitors | 12 from 8 nations |
The men's 400 metre freestyle event at the 2025 SEA Games will take place on 15 December 2025 at the SAT Swimming Pool in Bangkok, Thailand.
All times are Indochina Standard Time (UTC+07:00)
| Date | Time | Event |
|---|---|---|
| Monday, 15 December 2025 | 9:32 | Heats |
| 18:32 | Final |
Prior to this competition, the existing world, Asian, and Southeast Asian Games records were as follows.
| World Record |  Lukas Märtens (GER) | 3:39.96 | Stockholm, Sweden | 12 April 2025 |
| Asian Record |  Sun Yang (CHN) | 3:40.14 | London, United Kingdom | 28 July 2012 |
| Games Record |  Nguyễn Huy Hoàng (VIE) | 3:48.06 | Hanoi, Vietnam | 16 May 2022 |
| Rank | Heat | Lane | Swimmer | Nationality | Time | Notes |
|---|---|---|---|---|---|---|
| 1 | 2 | Peerapat Settheechaichana |  Thailand | |||
| 1 | 3 | Nicholas Karel Subagyo |  Indonesia | |||
| 1 | 4 | Khiew Hoe Yean |  Malaysia | |||
| 1 | 5 | Trần Văn Nguyễn Quốc | Vietnam | |||
| 1 | 6 | Russel Pang |  Singapore | |||
| 2 | 2 | Khomchan Wichachai | Thailand | |||
| 2 | 3 | Muhammad Dhuha Zulfikry | Malaysia | |||
| 2 | 4 | Nguyễn Huy Hoàng | Vietnam | |||
| 2 | 5 | Glen Lim | Singapore | |||
| 2 | 6 | Made Aubrey Jaya | Indonesia |
| Rank | Lane | Swimmer | Nationality | Time | Notes |
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