Sri Lanka at the 2012 Summer Olympics 50 metre rifle prone competitions in the qualifying round but did not score enough points to advance. Neither Unamboowe nor Udugampola, competing in the men's 100 metre backstroke and women's 100 metre freestyle, were fast enough to advance beyond their initial heats. Sri Lanka participated in sixteen Olympic Games between its debut at the 1948 Summer Olympics in London, United Kingdom and the 2012 Olympic Games held in the same city. The sole exception was the 1976 Summer Olympics in Montreal. Though it was widely believed the country was participating in a boycott relating to the tour of South Africa
Brunei at the 2012 Summer Olympics they failed to meet the required qualifying times for their events. Mahusin was the flag bearer for the opening ceremony while Lim held it at the closing ceremony. All three athletes failed to advance beyond the heat stages of their respective events, but Mahusin and Lim achieved new national records in athletics and swimming. Although Brunei first participated in the Summer Olympics in the 1988 Summer Olympics in Seoul, South Korea, it was only represented by one official. It would not be until the 1996 Summer Olympics in Atlanta, United States that the country would send athletes to the Games.