Russia, Germany, China, Great Britain, Australia, and the Netherlands were traditionally strong track cycling nations.

A preview at Olympics.com also identified Azizulhasni Awang of Malaysia, the 2016 Olympic bronze medalist and 2017 World Champion, as a significant contender.

The Keirin final was won in unusual and dramatic style by the reigning champion, Jason Kenny of Great Britain in what would be his last race, riding in position one behind the derny.

Taking the drag of the derny in what is often considered an unhelpful position for the final sprint, Kenny's superior experience and racecraft led him to take advantage of the nervous Matthew Glaetzer in second wheel to gradually create a gap of a few bike lengths over the field just as the derny prepared to pull off.

[11] It also made Kenny one of the elite number of Olympians to have successfully defended an Olympic gold medal in three different events (in Kenny's case, team sprint between 2008 and 2016, sprint between 2012 and 2016 and keirin between 2016 and 2020), the others being Michael Phelps, Ray Ewry, Larisa Latynina, Jenny Thompson and Sawao Kato.