World champions South Africa and Australia will play Scotland at Murrayfield in November next year.
The Scots will also take on a third side still to be confirmed in their autumn series, which will take place on the weekends of 6, 13 and 20 November.
Dave Rennie left Glasgow Warriors this year to take on the Wallabies job.
Scotland are currently competing in the Autumn Nations Cup and Gregor Townsend's side face Ireland in Saturday's third place play-off.
"Fans, players and coaches will be looking forward to next year," said Townsend, Rennie's predecessor at Warriors. "The Autumn Nations Cup has been a great way for international rugby to resume in these difficult times.
"The autumn internationals in 2021 will be another opportunity for our players to represent their country, hopefully with our fans in attendance, and provides the team with a different challenge and exciting challenge as a result."
Meanwhile, Zander Fagerson believes Scotland have "grown as a team" since suffering a deflating defeat against Ireland 10 months ago.
The last time they took on Ireland at the Aviva Stadium, it resulted in a 19-12 Six Nations loss.
"We were pretty gutted and kicking ourselves after that Ireland game in February," Glasgow prop Fagerson said.
"We've got a few new threats and improved in certain areas, particularly the contact area, which wasn't where it needed to be in February, when we let them off the hook a few times.
"It is a big opportunity against a top-class team, so we're looking forward to going there and hopefully finishing third in this competition."
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