Brunei at the 2020 Summer Olympics

Brunei, officially known as Brunei Darussalam, competed at the 2020 Summer Olympics in Tokyo. Originally scheduled to take place from 24 July to 9 August 2020, the Games were postponed to 23 July to 8 August 2021, due to the COVID-19 pandemic. This was the nation's eighth appearance at the Summer Olympics since its debut at the 1988 Summer Olympics. Brunei failed to register any athletes in two editions of the Games: 1992 in Barcelona and 2008 in Beijing.

Competitors
The following is the list of number of competitors in the Games.

Athletics
Brunei received a universality slot from the World Athletics to send a male track and field athlete to the Olympics.


 * Key
 * Note–Ranks given for track events are within the athlete's heat only
 * Q = Qualified for the next round
 * q = Qualified for the next round as a fastest loser or, in field events, by position without achieving the qualifying target
 * NR = National record
 * N/A = Round not applicable for the event
 * Bye = Athlete not required to compete in round


 * Track & road events

Swimming
Brunei received a universality invitation from FINA to send a top-ranked male swimmer in his respective individual events to the Olympics, based on the FINA Points System of June 28, 2021.