The Brunei delegation included three athletes: Ak Hafiy Tajuddin Rositi, Maziah Mahusin, and swimmer Anderson Lim.

[4] On 13 February it was agreed by Brunei's Ministry of Culture, Youth and Sports committee that one participant in athletics and swimming would be sent to the Games.

[5] In the months prior to the London Games, Brunei attracted media attention as it was noted that the nation was one of only three countries—along with Saudi Arabia and Qatar—never to have sent a female athlete to the Olympics.

[6] The delegation to London comprised runners Ak Hafiy Tajuddin Rositi and Maziah Mahusin and swimmer Anderson Lim.

[8][9] Ak Hafiy Tajuddin Rositi was the oldest athlete to compete for Brunei at the London Games at age 21.

Overall Rositi finished 45th out of 47 runners,[a] and was unable to advance into the semi-finals because he was 3.67 seconds slower than the slowest athlete in his heat who made the later stages.

[12] At age 19 and competing at her first Summer Olympics, Maziah Mahusin was the first female athlete to represent Brunei at the Games.

[10][13] In an interview with Reuters before the Games Mahusin said she felt "deeply honoured" to represent her country and that it was "a dream come true" that she was selected.