Vanuatu competed at the 2004 Summer Olympics in Athens, Greece, which was held from 13 to 29 August 2004. The nation's appearance at the 2004 Athens Games marked its fifth appearance at the Summer Olympics since its debut at the 1988 Summer Olympics.
Iceland competed at the 1992 Summer Olympics in Barcelona, Spain.
São Tomé and Príncipe competed at the 2000 Summer Olympics in Sydney, Australia, which took place from 15 September to 1 October 2000. This marked the country's second appearance at the Summer Olympics, following its debut at the 1996 Summer Olympics. Its delegation consisted of two track and field athletes, Arlindo Pinheiro and Naide Gomes, who were selected to represent the country via wildcards, as the country had no athletes that met either the "A" or "B" qualifying standards. Pinheiro competed in the men's 110 m hurdles and Gomes competing in the women's 100 m hurdles, respectively. Gomes was selected as the flag bearer for the opening ceremony. Despite Pinheiro setting a national record with his time, ultimately, neither athlete progressed beyond the heats of their respective events.
Portugal's first participation in the Summer Olympic Games took place at the 1912 Summer Olympics in Stockholm, Sweden. The nation was represented by a delegation of six competitors, who took part in three sports but failed to win a medal. The Portuguese debut participation was marked by the death of flag bearer Francisco Lázaro, who succumbed to electrolytic imbalance after the marathon race.
Hungary competed at the 1912 Summer Olympics in Stockholm, Sweden. Austrian and Hungarian results at early Olympic Games are generally kept separate despite the union of the two nations as Austria-Hungary at the time. 121 competitors, all men, took part in 52 events in 11 sports.
Mexico competed at the 1956 Summer Olympics in Melbourne, Australia. 24 competitors, 21 men and 3 women, took part in 20 events in 10 sports.
Luxembourg competed at the 1920 Summer Olympics in Antwerp, Belgium.
Iceland competed at the 1948 Summer Olympics in London, England. The country was represented by 1 man in Art competitions, 11 men in athletics and 5 men and 3 women in swimming.
Iceland competed at the 1952 Summer Olympics in Helsinki, Finland.
Iceland competed at the 1956 Summer Olympics in Melbourne, Australia. As a partial support to the Dutch-led boycott, Icelandic athletes under the Olympic flag instead of the national flag. Vilhjálmur Einarsson won the first ever Olympic medal for his country.
Iceland competed at the 1964 Summer Olympics in Tokyo, Japan. The Games were hosted from October 11, 1964, to October 24, 1964.
Athletes from Iceland first participated at the Olympic Games in 1908.
Palau competed at the 2008 Summer Olympics in Beijing, China. Palau's Olympic delegation was led by Frank Kyota, the President of the Palau National Olympic Committee, and consisted of five athletes, three team officials and four coaches. This was an increase from the nation's two previous appearances at the Summer Olympic Games; four athletes had been sent to both the Sydney and Athens Games. Palau's Olympic team was one of the 117 that won no medals at the Games.
Albania sent a team to compete at the 2008 Summer Olympics in Beijing, China which was organised by the National Olympic Committee of Albania.
Peru competed in the 2008 Summer Olympics which was held in Beijing, People's Republic of China from August 8 to August 24, 2008. The country was represented by at least twelve athletes, who competed in the fields of athletics, badminton, swimming, taekwondo, shooting, wrestling, judo and fencing.
Central African Republic competed at the 2012 Summer Olympics in London, United Kingdom from 27 July to 12 August 2012. This was the nation's ninth appearance at the Olympics, excluding three games after its national debut in 1968.
Madagascar competed at the 2012 Summer Olympics in London, United Kingdom from 27 July to 12 August 2012. This was the nation's eleventh appearance at the Olympics, excluding the 1976 Summer Olympics in Montreal and the 1988 Summer Olympics in Seoul, because of the African and North Korean boycott.
Bahrain competed at the 2016 Summer Olympics in Rio de Janeiro, Brazil, from 5 to 21 August 2016. This nation marked its ninth consecutive appearance at the Summer Olympics.
Iceland 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, because of the COVID-19 pandemic.
Kosovo (KOS) competed at the 2020 Summer Olympics in Tokyo, Japan, represented by the Olympic Committee of Kosovo (KOK/OKK). The nation had previously participated in the Summer Olympic Games on one occasion in 2016. A total of 11 athletes, five men and six women, were selected by the national committee to compete in six sports. Initially scheduled to take place during the summer of 2020, the games were postponed to 23 July to 8 August 2021 in relation to the pandemic of the coronavirus disease 2019 (COVID-19).
