# 2018 FINA World Swimming Championships (25 m) – Men's 100 metre backstroke

The men's 100 metre backstroke competition of the 2018 FINA World Swimming Championships (25 m) was held on 11 and 12 December 2018.

## Records

Prior to the competition, the existing world and championship records were as follows.
| | Name | Nation | Time | Location | Date |
| World record | Xu Jiayu | China | 48.88 | Tokyo | 11 November 2018 |
| Championship record | Stanislav Donets | Russia | 48.95 | Dubai | 19 December 2010 |

## Results
### Heats

The heats were started on 11 December at 10:52.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 3 | 4 | Guilherme Guido | Brazil | 49.57 | Q, SA |
| 2 | 4 | 8 | Ryan Murphy | United States | 49.72 | Q |
| 3 | 4 | 4 | Xu Jiayu | China | 49.83 | Q |
| 4 | 3 | 0 | Matt Grevers | United States | 50.12 | Q |
| 5 | 4 | 3 | Robert Glință | Romania | 50.22 | Q |
| 6 | 4 | 5 | Mitch Larkin | Australia | 50.27 | Q |
| 7 | 3 | 3 | Christian Diener | Germany | 50.28 | Q |
| 8 | 5 | 5 | Simone Sabbioni | Italy | 50.62 | Q |
| 9 | 3 | 5 | Radosław Kawęcki | Poland | 50.73 | Q |
| 9 | 5 | 6 | Ryosuke Irie | Japan | 50.73 | Q |
| 11 | 5 | 4 | Kliment Kolesnikov | Russia | 50.76 | Q |
| 12 | 4 | 6 | Apostolos Christou | Greece | 50.92 | Q |
| 13 | 3 | 6 | Guilherme Basseto | Brazil | 50.94 | Q |
| 14 | 3 | 1 | Anton Lončar | Croatia | 51.09 | Q |
| 15 | 5 | 3 | Andrei Shabasov | Russia | 51.16 | Q |
| 16 | 2 | 4 | Thomas Ceccon | Italy | 51.30 | Q |
| 17 | 4 | 1 | Gabriel Lopes | Portugal | 51.48 | NR |
| 18 | 4 | 7 | Viktar Staselovich | Belarus | 51.59 | |
| 19 | 5 | 2 | Markus Lie | Norway | 51.60 | |
| 20 | 3 | 8 | Bradlee Ashby | New Zealand | 51.61 | |
| 21 | 5 | 7 | Tomáš Franta | Czech Republic | 51.82 | |
| 22 | 2 | 3 | Omar Pinzón | Colombia | 51.87 | |
| 23 | 4 | 2 | Yuma Edo | Japan | 51.88 | |
| 24 | 3 | 9 | Conor Ferguson | Ireland | 52.04 | |
| 25 | 3 | 7 | Hugo González | Spain | 52.05 | |
| 26 | 3 | 2 | Cătălin Ungur | Romania | 52.28 | |
| 27 | 5 | 8 | Bernhard Reitshammer | Austria | 52.34 | |
| 28 | 5 | 1 | Li Guangyuan | China | 52.36 | |
| 29 | 2 | 2 | Paul Lê Nguyễn | Vietnam | 52.48 | |
| 30 | 5 | 0 | Dávid Földházi | Hungary | 52.60 | |
| 31 | 5 | 9 | İskender Başlakov | Turkey | 52.79 | |
| 32 | 4 | 0 | Thierry Bollin | Switzerland | 53.02 | |
| 33 | 4 | 9 | Chuang Mu-lun | Chinese Taipei | 53.81 | |
| 34 | 1 | 8 | Merdan Atayev | Turkmenistan | 54.29 | |
| 35 | 2 | 7 | Ģirts Feldbergs | Latvia | 54.79 | |
| 36 | 1 | 1 | Cadell Lyons | Trinidad and Tobago | 54.92 | |
| 37 | 2 | 5 | Lee Ju-ho | South Korea | 55.02 | |
| 38 | 2 | 6 | Armando Barrera Aira | Cuba | 55.07 | |
| 39 | 2 | 9 | Filippos Iakovidis | Cyprus | 55.87 | NR |
| 40 | 2 | 0 | Matthew Mays | United States Virgin Islands | 56.09 | |
| 41 | 1 | 4 | Eisner Barberena Espinoza | Nicaragua | 56.78 | |
| 42 | 1 | 7 | Heriniavo Michael Rasolonjatovo | Madagascar | 59.02 | |
| 43 | 1 | 5 | Abdulaziz Al-Obaidly | Qatar | 59.41 | |
| 44 | 1 | 3 | Bede Aitu | Cook Islands | 59.68 | |
| 45 | 1 | 2 | Omar Al-Rowaila | Bahrain | 1:02.90 | |
| 46 | 1 | 6 | Joel Gjini | Albania | 1:05.00 | |
| 47 | 1 | 0 | Ali Imaan | Maldives | 1:08.71 | |
| | 2 | 8 | Driss Lahrichi | Morocco | DSQ | |

### Semifinals

The semifinals were started on 11 December at 19:17.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 2 | 5 | Xu Jiayu | China | 49.21 | Q |
| 2 | 2 | 4 | Guilherme Guido | Brazil | 49.45 | Q, SA |
| 3 | 1 | 4 | Ryan Murphy | United States | 49.52 | Q |
| 4 | 2 | 7 | Kliment Kolesnikov | Russia | 49.62 | Q |
| 5 | 1 | 5 | Matt Grevers | United States | 49.97 | Q |
| 6 | 2 | 3 | Robert Glință | Romania | 49.98 | Q, NR |
| 7 | 2 | 6 | Christian Diener | Germany | 50.04 | Q |
| 8 | 1 | 3 | Mitch Larkin | Australia | 50.12 | Q |
| 9 | 1 | 6 | Simone Sabbioni | Italy | 50.21 | |
| 10 | 2 | 8 | Andrei Shabasov | Russia | 50.32 | |
| 11 | 2 | 2 | Radosław Kawęcki | Poland | 50.43 | |
| 12 | 1 | 2 | Ryosuke Irie | Japan | 50.45 | |
| 13 | 2 | 1 | Guilherme Basseto | Brazil | 50.83 | |
| 14 | 1 | 7 | Apostolos Christou | Greece | 50.91 | |
| 15 | 1 | 8 | Thomas Ceccon | Italy | 50.96 | |
| 16 | 1 | 1 | Anton Lončar | Croatia | 51.20 | |

### Final

The final was held on 12 December at 19:08.
| Rank | Lane | Name | Nationality | Time |
| | 3 | Ryan Murphy | United States | 49.23 |
| | 4 | Xu Jiayu | China | 49.26 |
| | 6 | Kliment Kolesnikov | Russia | 49.40 |
| 4 | 8 | Mitch Larkin | Australia | 49.46 |
| 5 | 5 | Guilherme Guido | Brazil | 49.75 |
| 6 | 2 | Matt Grevers | United States | 50.02 |
| 7 | 1 | Christian Diener | Germany | 50.24 |
| 8 | 7 | Robert Glință | Romania | 50.36 |