Sierra Leone competed at the 2004 Summer Olympics in Athens, Greece, from 13 to 29 August 2004. This was the nation's eighth appearance at the Summer Olympics since its debut in the 1968 Summer Olympics. The Sierra Leone delegation included two track and field athletes; Lamin Tucker and Hawanatu Bangura, both of whom were sprinters that were selected via winning an event in Freetown, as the nation had no athletes that met the "A" or "B" standards in any event. Bangura was selected as flag bearer for the opening ceremony. Neither of the two athletes progressed beyond the heats.
Sierra Leone has sent athletes to every Summer Olympic Games since 1968 with the exception of 1972 and 1976, but the nation has yet to win an Olympic medal. No athletes from Sierra Leone have competed in any Winter Olympic Games.
Kosovo made its Olympic debut as a member state in 2016. Its team is organized by the Olympic Committee of Kosovo (OCK), created in 1992 and recognized by the International Olympic Committee on 9 December 2014. It won its first medal in its debut appearance in 2016, when judoka Majlinda Kelmendi took gold in the women's -52 kg category. In the 2020 Tokyo Olympics, Nora Gjakova won gold in the women's judo -57 kg class, and Distria Krasniqi won gold in the women's judo -48 kg class.
Sierra Leone competed at the 2010 Summer Youth Olympics, the inaugural Youth Olympic Games, held in Singapore from 14 August to 26 August 2010. The nation was represented by the National Olympic Committee of Sierra Leone, which sent a total of three athletes to compete in one sport, athletics. The flagbearer at the opening ceremony for the nation was athlete Nenneh Barrie. Sierra Leone's Olympic team was one of the 106 that did not win a single medal at the Games.
Chad competed at the 2012 Summer Olympics in London, which was held from 27 July to 12 August 2012. This marked the nation's eleventh appearance at the Summer Olympics since its debut in the 1964 Summer Olympics. The Chadian delegation included track and field athlete Hinikissia Ndikert and judoka Carine Ngarlemdana. Ngarlemdana was the flag bearer for the opening ceremony and Ndikert was the flag bearer for the closing ceremony. Neither of Chad's athletes progressed beyond the first round of their events. Chad was one of only two countries to have a female-only team at the 2012 games.
Sierra Leone competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This marked the nation's tenth appearance at the Summer Olympics since its debut in the 1968 Summer Olympics. The Sierra Leone delegation included two track and field athletes; Ibrahim Turay, a sprinter and Ola Sesay, a long jumper. Sesay and Turay were selected as flag bearers for the opening and closing ceremonies respectively. Neither of the two athletes progressed beyond the first round.
Ola Sesay is a Sierra Leonean long jumper. She competed at the 2012 Summer Olympics and was the flag bearer of Sierra Leone during the 2012 Summer Olympics opening ceremony.
Estefania Priscila García Mendoza is an Ecuadorian judoka. At the 2012 Summer Olympics she competed in the Women's 63 kg, but was defeated in the second round.
Sierra Leone competed at the 2016 Summer Olympics in Rio de Janeiro, Brazil, from 5 to 21 August 2016. This was the nation's eleventh appearance at the Summer Olympics since its debut in 1968, except for two occasions. Sierra Leone failed to register any athletes at the 1972 Summer Olympics in Munich, and also joined the rest of the African nations to boycott the 1976 Summer Olympics in Montreal.
Taciana Rezende de Cesar Baldé is a judoka. Born in Brazil to a Bissau-Guinean father, she represented her country of birth before pledging her international allegiance to Guinea-Bissau. She competed at the 2016 Summer Olympics in the women's 48 kg event, in which she was eliminated in the second round by Galbadrakhyn Otgontsetseg She was the flag bearer for Guinea-Bissau during the closing ceremony.
Sulaiman Hamad is a Saudi Arabian judoka. He competed at the 2016 Summer Olympics in the men's 66 kg, in which he was eliminated in the second round by Davaadorjiin Tömörkhüleg. He was the flag bearer for Saudi Arabia at the Parade of Nations.
Chamara Repiyallage also known as Chamara Dharmawardana is a Sri Lankan judoka. He is also attached with Sri Lanka Air Force.
David Peter Sawyerr is a Sierra Leonean sprinter. He competed in the men's 200 metres at the 1984 Summer Olympics. Sawyerr was the flag bearer for Sierra Leone in the opening ceremony.
During the Parade of Nations within the Tokyo 2020 Summer Olympics opening ceremony, which took place on 23 July 2021, athletes and officials from each participating team entered the Olympic Stadium preceded by their flag and placard bearer. Each flag bearer will have been chosen either by the team's National Olympic Committee or by the athletes themselves. For the first time, each team had the option to allow two flag bearers, one male and one female, in an effort to promote gender equality. These Olympics were postponed from 2020 due to the COVID-19 pandemic and due security measures some countries prevented their athletes to participate on event.
Kiribati competed at the 2020 Summer Olympics in Tokyo. Originally scheduled to take place from 24 July to 9 August 2020, it was postponed to 23 July to 8 August 2021, due to the COVID-19 pandemic. This marked the nation's fifth appearance at the Olympics.
Comoros 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. It was the nation's seventh consecutive appearance at the Summer Olympics.
Sierra Leone competed at the 2020 Summer Olympics in Tokyo. Originally scheduled to for 24 July to 9 August 2020, the Games were postponed to 23 July to 8 August 2021 due to the COVID-19 pandemic. It was the nation's twelfth appearance at the Summer Olympics, having appeared at all but two Games since its debut in 1968; Sierra Leone failed to register any athletes at the 1972 Summer Olympics in Munich and also joined the rest of the African nations to boycott the 1976 Summer Olympics in Montreal.
Cedric Bessi is a Monégasque judoka.
Damiella Nomenjanahary is a Malagasy judoka.
Sabiana Anestor is a Haitian judoka. She competed in the women's half lightweight event at the 2020 Summer Olympics. She served the flag bearer with Darrelle Valsaint at the opening ceremony.
Sierra Leone 
