The opening ceremony of the delayed 2020 Summer Olympics took place on 23 July 2021 at Olympic Stadium, Tokyo, and was formally opened by Emperor Naruhito. As mandated by the Olympic Charter, the proceedings combined the formal and ceremonial opening of this international sporting event, including welcoming speeches, hoisting of the flags and the parade of athletes, with an artistic spectacle to showcase the host nation's culture and history. The majority of the artistic spectacle was pre-recorded, with live segments performed adhering to social distancing to athletes, officials and a small VIP audience. The ceremony marked the 125th anniversary of the 1896 Summer Olympics in Athens—the inaugural edition of the modern Olympic Games.

The theme of the 2020 Olympic and Paralympic Ceremonies was Moving Forward, which referenced the global COVID-19 pandemic. The opening ceremony theme was the Tokyo 2020 motto United by Emotion, with the aim to "reaffirm the role of sport and the value of the Olympic Games." The ceremony expressed responses to the pandemic by the athlete community, congratulate front-line workers, and included themes of lament, waiting and hope. The ceremony also showcased Japanese popular culture such as Japanese theater, video games, and variety shows, such as Kasou Taishou. For the second time in an Olympic opening ceremony, a minute of silence was observed in honor of the Munich massacre's 50th anniversary at the 1972 Summer Olympics and the 10th anniversary of the Tōhoku disaster, happened in 2011.