[3] British athletes have appeared in every Summer Olympic Games of the modern era, alongside those of Australia, France, Greece, and Switzerland, although Great Britain is the only team to have won at least one gold medal at all of them.
In the pool, Adam Peaty became the first British swimmer to successfully defend an Olympic gold medal, winning the 100 metre breaststroke for the second time.
This included a 1–2 finish in the final of the Men's 200m freestyle for Duncan Scott (who took silver) and Tom Dean (who took gold) which was the first time British swimmers had achieved this in any Olympic swimming event since 1908.
On 4 August Sky Brown became the youngest British Olympian ever to win a medal when she won bronze in the Women's Park Skateboarding at the age of 13 years and 28 days.
His wife Laura Kenny lost her omnium title after a major crash in the opening scratch race, and only managed a silver medal in the women's team pursuit.
This was partly due to unfortunately timed injuries to reigning world champions Dina Asher-Smith (200 metres) and Katarina Johnson-Thompson (Heptathlon) who were seen as Britain's best medal hopes in the athletics events.
Indeed, the weightlifting event at the Games was a significant success for Great Britain, with top-seven finishes for all four selected lifters, and Sarah Davies coming agonisingly close to winning a second silver medal in the −64 kg class.
[9] The team included nine sets of siblings: Tom and Emily Ford (Rowing), Jennifer and Jessica Gadirova (Gymnastics), Charlotte and Mathilda Hodgkins-Byrne (Rowing), Joe and Max Litchfield (Swimming), Luke and Pat McCormack (Boxing), Andy and Jamie Murray (Tennis), Tiffany Porter and Cindy Sember (Athletics), Hannah and Jodie Williams (Athletics), and Adam and Simon Yates (Cycling).
[11] British archers qualified each for the men's and women's events by reaching the quarterfinal stage of their respective team recurves at the 2019 World Archery Championships in 's-Hertogenbosch, Netherlands.
[12] The rules of qualification also stipulate that a nation that qualifies at least one male and one female archer, as Great Britain have done, is automatically entered in the mixed team event.
This slot was then superseded by the top seven finish achieved by Great Britain itself at the final FINA Artistic Swimming Olympic Qualification Tournament.
[25] Ben Lane and Sean Vendy were selected to compete in the men's doubles even though Rio 2016 bronze medallists Marcus Ellis and Chris Langridge finished ahead of them in the rankings.
British equestrians qualified a full squad in the team dressage, eventing, and jumping competitions by virtue of a top-six finish at the 2018 FEI World Equestrian Games in Tryon, North Carolina, United States in dressage and eventing, and a top-three finish among eligible nations in the jumping competition at the 2019 FEI European Championships in Rotterdam, Netherlands.
2019 world silver medallist Marcus Mepstead claimed a spot in the men's foil as one of the two highest-ranked fencers vying for qualification from Europe in the FIE Adjusted Official Rankings.
[64] On 24 May 2021, Team GB announced the selection of the four members of the men's squad including reigning individual pommel horse and floor exercise champion Max Whitlock together with three debutants.
[67][68] Great Britain secured a second quota when Rio silver medallist Bryony Page finished fourth in the 2020/21 Trampoline World Cup series.
On 5 July 2021, Team GB announced the judokas who will compete in Tokyo, including debutant Sarah Adlington in the women's heavyweight category, who had been awarded a continental quota following the official withdrawal of Smythe-Davis.
The England men's and women's teams earned the right to represent the British unions in that stage of their respective competitions, but failed to qualify for the Olympic events through a top four finish.
[82][83] On 1 October 2019, Team GB announced the names of the first twelve sailors selected for the Tokyo 2020 regatta, including Saskia Tidey, who previously competed for Ireland in Rio 2016, defending champions Giles Scott (Finn) and Hannah Mills (women's 470), and London 2012 silver medallists Luke Patience (men's 470) and Stuart Bithell (49er).
[86] M = Medal race; DSQ = Disqualification; EL = Eliminated – did not advance into the medal race; UFD = "U" Flag disqualification British shooters achieved quota places for the following events by virtue of their best finishes at the 2018 ISSF World Championships, the 2019 ISSF World Cup series, European Championships or Games, and European Qualifying Tournament, as long as they obtained a minimum qualifying score (MQS) by 31 May 2020.
[88] Amber Hill secured a quota in the women's skeet after finishing at the top of the qualifying rankings for that event by winning the ISSF World Cup in New Delhi on 21 March 2021.
The reigning European and World champion, who had twice broken his back playing rugby as a teenager,[93] missed his first three targets but then hit 14 in a row to secure the bronze medal.
Sky Brown and Bombette Martin qualified among the top 16 eligible skateboarders in the women's park, respectively, based on the World Skate Olympic Rankings of 30 June 2021.
Shauna Coxsey qualified directly for the women's combined event, by advancing to the final stage and securing one of the seven provisional berths at the 2019 IFSC World Championships in Hachioji, Japan.
The standard is typically well in advance of the qualification time set by the international federation FINA; therefore, the number and identity of swimmers who will represent Great Britain will not be known until the period concludes.
In June 2021, Hector Pardoe and Alice Dearing won quotas in the men's and women's 10 km marathon by virtue of finishing first and fourth respectively in the final qualifying event in Setúbal, Portugal.
[106] During the competition Adam Peaty won Team GB's first gold medal of the Games and became the first British swimmer to successfully defend an Olympic title, winning the men's 100 m breaststroke.
Two-time Olympian Liam Pitchford and double Commonwealth Games medallist Tin-Tin Ho were automatically selected among the top ten table tennis players vying for qualification in their respective singles events based on the ITTF Olympic Rankings of 1 June 2021.
In addition to these players Cameron Norrie also qualified through the rankings but declined the opportunity to attend the Games due to other professional commitments, while Kyle Edmund was recovering from surgery.
This left Heather Watson as the only female player in the squad, and meant that, in the absence of a potential replacement (no British woman being ranked high enough to qualify), there would be no entry in the Women's doubles tournament.