| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 8 | 5 | Xu Jiayu | | 50.21 | Q |
| 2 | 8 | 3 | Mitch Larkin | | 50.22 | Q |
| 3 | 8 | 4 | Radosław Kawęcki | | 50.63 | Q |
| 4 | 6 | 7 | Jacob Pebley | | 50.64 | Q |
| 5 | 7 | 3 | Junya Koga | | 50.71 | Q |
| 5 | 7 | 4 | Andrey Shabasov | | 50.71 | Q |
| 7 | 8 | 9 | Grigoriy Tarasevich | | 50.93 | Q |
| 8 | 7 | 5 | Masaki Kaneko | | 51.01 | Q |
| 9 | 8 | 6 | Robert Glință | | 51.03 | Q |
| 10 | 6 | 4 | Pavel Sankovich | | 51.07 | Q |
| 11 | 6 | 3 | Tomasz Polewka | | 51.11 | Q |
| 12 | 6 | 5 | Bobby Hurley | | 51.13 | Q |
| 13 | 7 | 7 | Javier Acevedo | | 51.32 | Q |
| 14 | 6 | 2 | Miguel Ortiz-Cañavate | | 51.50 | Q |
| 15 | 6 | 6 | Danas Rapšys | | 51.61 | Q |
| 15 | 7 | 6 | David Gamburg | | 51.61 | Q |
| 17 | 8 | 7 | Thomas Avetand | | 51.80 | |
| 18 | 4 | 3 | Anton Loncar | | 51.86 | |
| 19 | 6 | 8 | Ádám Telegdy | | 52.02 | |
| 20 | 7 | 9 | Apostolos Christou | | 52.07 | NR |
| 21 | 8 | 0 | Gabriel Lopes | | 52.21 | |
| 22 | 8 | 8 | Tomáš Franta | | 52.24 | |
| 23 | 6 | 1 | Oleg Garasymovytch | | 52.36 | |
| 24 | 5 | 1 | Lê Nguyễn Paul | | 52.57 | NR |
| 25 | 7 | 8 | Charlie Boldison | | 52.61 | |
| 26 | 7 | 1 | Viktar Staselovich | | 52.62 | |
| 27 | 5 | 6 | Charles Hockin Brusquetti | | 52.80 | NR |
| 28 | 5 | 3 | Markus Thormeyer | | 53.15 | |
| 29 | 7 | 2 | Iskender Baslakov | | 53.19 | |
| 30 | 6 | 9 | Mattias Carlsson | | 53.34 | |
| 31 | 5 | 2 | Ricky Ellis | | 53.37 | |
| 31 | 7 | 0 | Ryan Pini | | 53.37 | |
| 33 | 5 | 8 | Trần Duy Khôi | | 53.64 | |
| 34 | 5 | 5 | Gaston Hernandez | | 53.71 | |
| 35 | 8 | 1 | Magnus Jakupsson | | 53.89 | |
| 36 | 5 | 7 | Christopher Courtis | | 53.94 | NR |
| 37 | 5 | 0 | David Adalsteinsson | | 54.12 | |
| 38 | 5 | 4 | Kristinn Þórarinsson | | 54.43 | |
| 39 | 5 | 9 | Kristóf Rasovszky | | 54.52 | |
| 40 | 4 | 5 | Francis Fong | | 54.89 | |
| 41 | 1 | 1 | Boris Kirillov | | 54.90 | NR |
| 42 | 4 | 6 | Jarryd Baxter | | 55.18 | |
| 43 | 4 | 9 | Keanan Dols | | 55.39 | NR |
| 44 | 4 | 7 | Yeziel Morales Miranda | | 55.68 | |
| 45 | 3 | 7 | Adel Elfakir | | 55.83 | NR |
| 46 | 4 | 8 | Gorazd Chepishevski | | 55.98 | NR |
| 47 | 3 | 0 | Syed Hasseb Tariq | | 56.79 | NR |
| 48 | 3 | 4 | Adil Assouab | | 56.82 | |
| 49 | 3 | 6 | Jarod Alexander Arroyo | | 57.32 | |
| 50 | 2 | 5 | Jordan Gonzalez | | 57.65 | NR |
| 51 | 3 | 8 | Hernan Gonzalez Medina | | 57.68 | NR |
| 52 | 4 | 2 | Ivo Kunzle Savastano | | 57.78 | |
| 53 | 4 | 0 | Eisner Barberena Espinoza | | 57.89 | NR |
| 54 | 1 | 8 | Sebastien Kouma | | 58.03 | NR |
| 55 | 2 | 4 | Steven Kimani Maina | | 58.18 | |
| 56 | 3 | 1 | Alex McCallum | | 58.38 | |
| 57 | 3 | 5 | Abdullah Al-Doori | | 58.63 | NR |
| 58 | 2 | 3 | William Clark | | 58.77 | NR |
| 59 | 3 | 3 | Yum Cheng Man | | 59.71 | |
| 60 | 3 | 2 | Heriniavo Michael Rasolonjatovo | | | NR |
| 61 | 1 | 7 | Mohammad Juwel Ahmed | | | NR |
| 62 | 2 | 6 | Kennet Libohova | | | |
| 63 | 2 | 2 | Livingston Aika | | | |
| 64 | 2 | 1 | Daryl Appleton | | | NR |
| 65 | 2 | 8 | Elijah James Cruz | | | |
| 66 | 2 | 0 | Temaruata Strickland | | | NR |
| 67 | 1 | 4 | Tongli Panuve | | | NR |
| 68 | 3 | 9 | Naveed Hussian | | | |
| 69 | 2 | 9 | Cruz Halbich | | | NR |
| 70 | 1 | 5 | Aaron de Freitas | | | |
| 71 | 1 | 2 | Joseph Richard Sumari | | | |
| 72 | 1 | 6 | Dennis Hamis Mhini | | | |
| 6 | 0 | Michael Taylor | | | |
| 1 | 3 | Tanner Poppe | | | |
| 2 | 7 | Hasan Isam Sadeq | | | |
| 4 | 1 | Driss Lachrichi | | | |
| 4 | 4 | Daniil Bukin | | | |
| 8 | 2 | Dylan Carter | | | |
