Japanese prime minister Fumio Kishida confirmed the change on Wednesday (24 August).
Currently, travellers entering Japan must show proof of a negative test taken within 72 hours of departure.
The country reopened to tourists travelling on guided tours only on 10 June.
Kishida said his government also plans to increase the daily cap for incoming travellers, currently set at 20,000, "as soon as possible."
Fully vaccinated travellers are classed as those who have received three doses of a certified Covid vaccine.