The Wallabies will face Japan in Oita on Saturday 23 October, as confirmed by Japan Rugby Union.
The match will kick off the Spring Tour, which will see Australia head to Europe to face Scotland, England and Wales.
It will be their first meeting for the two nations since November 2017, when the Wallabies defeated the Brave Blossoms 63-30 in Yokohama.
“We’re really looking forward to squaring off against Japan. They showed everyone at the World Cup in 2019 that they are a top nation and can match it with the best," Wallabies coach Dave Rennie said in a statement.
“Jamie (Joseph) and Tony (Brown) have built a formidable squad that plays a really exciting, up-tempo style. We need to continue to test ourselves with this variety of play, so this is an important match for us as we continue to build ahead of the next World Cup in France.
“It’s been a really big year already for our squad with some starting back in February for Super Rugby AU so we will have to continue to manage the lads over the next month or two and into the Spring Tour in the UK.”
2021 Spring Tour (all times local)
Japan v Wallabies at Oita Stadium, Oita on Saturday 23 October at 1.45pm JST
Scotland v Wallabies at Murrayfield, Edinburgh on Sunday 7 November at 2.15pm GMT
England v Wallabies at Twickenham, London on Saturday 13 November at 5.30pm GMT
Wales v Wallabies at Principality Stadium, Cardiff on Saturday 20 November at 5.30pm GMT