| Birth Date: | 23 September 1987 |
| Birth Place: | Pavlodar, Soviet Union |
| Sport: | Athletics |
| Event: | 400m |
| Coach: | Viktor Kolyev |
Sergey Zaikov (Russian:Сергей Зайков; born 23 September 1987 in Pavlodar) is a Kazakhstani runner.[1] He competed at the 2012 Summer Olympics in the 400 m event, in which he was defeated after the first round.[2]
| Representing | ||||||
|---|---|---|---|---|---|---|
| 2008 | Asian Indoor Championships | Doha, Qatar | bgcolor=silver | 2nd | 400 m | 48.12 |
| 2009 | Asian Indoor Games | Hanoi, Vietnam | 3rd | 400 m | 47.63 | |
| Asian Championships | Guangzhou, China | 9th (h) | 400 m | 47.47 | ||
| 2010 | Asian Indoor Championships | Tehran, Iran | 6th | 400 m | 49.80 | |
| 3rd | 4 × 400 m relay | 3:17.06 (iNR) | ||||
| 2012 | Asian Indoor Championships | Hangzhou, China | 5th | 400 m | 48.97 | |
| Olympic Games | London, United Kingdom | 39th (h) | 400 m | 47.12 | ||
| 2014 | Asian Indoor Championships | Hangzhou, China | bgcolor=silver | 2nd | 400 m | 48.37 |
| bgcolor=gold | 1st | 4 × 400 m relay | 3:12.94 | |||
| Asian Games | Incheon, South Korea | 15th (sf) | 400 m | 47.33 | ||
| 8th | 4 × 400 m relay | 3:09.62 | ||||
| 2015 | Asian Championships | Wuhan, China | 12th (h) | 400 m | 47.51 | |
| 2017 | Asian Indoor and Martial Arts Games | Ashgabat, Turkmenistan | 13th (h) | 800 m | 1:56.59 | |
| – | 4 × 400 m relay | DNF | ||||
| 2018 | Asian Indoor Championships | Tehran, Iran | 8th (h) | 800 m | 1:58.64 | |
| bgcolor=silver | 2nd | 4 × 400 m relay | 3:11.68 | |||