Athletes began entering the Olympic Village after the residence for participants at the Tokyo Games was opened on Tuesday.
It was a low-key affair given the strict health protocols in place 10 days before the opening ceremony. Organisers last week decided to ban fans from all but a handful of events after the Japanese government instituted a state of emergency in Tokyo following a rise in coronavirus cases. The state of emergency went into force on Monday and runs through to August 22.
The protocols will be in effect throughout the Olympics, which open on July 23 and close on August 8.
Even so, Olympics chief Thomas Bach praised Tokyo as the "best-ever prepared" host city.
International Olympic Committee president Bach, who arrived in Japan last week and spent three days in quarantine, told Tokyo 2020 chief Seiko Hashimoto that organisers were "doing a fantastic job".
"You have managed to make Tokyo the best-ever prepared city for an Olympic Games," he was quoted as saying by AFP.
"This is even more remarkable under the difficult circumstances we all have to face."
Organisers have not specified how many athletes have already entered the Village. Strict coronavirus rules mean athletes can only enter the Village five days before their events and must leave within 48 hours of winning or being eliminated.