Steven Gardiner is a Bahamian track and field sprinter competing in the 400 metres and 200 metres. He is the 2020 Olympic and 2019 world champion in the 400 m, and also won the silver medal at the 2017 World Championships in that event. His winning time of 43.48 s from the 2019 World Championships is the Bahamian record and makes him the sixth-fastest man in the history of the event. Gardiner also owns the Bahamian records in the outdoor 300 m and 200 m, with times of 31.83 s and 19.75 s respectively, and the world best in the indoor 300 m at 31.56 s.

The 400 metres, or 400-meter dash, is a sprint event in track and field competitions. It has been featured in the athletics programme at the Summer Olympics since 1896 for men and since 1964 for women. On a standard outdoor running track, it is one lap around the track. Runners start in staggered positions and race in separate lanes for the entire course. In many countries, athletes previously competed in the 440-yard dash (402.336 m)—which is a quarter of a mile and was referred to as the "quarter-mile"—instead of the 400 m (437.445 yards), though this distance is now obsolete.