Portimao has not staged a grand prix before 2020, but hosted a pre-season test in 2009.
Portugal’s Algarve circuit is set to return to the Formula One calendar this season, taking the vacant slot left by Vietnam on May 2.
The BBC and Sky Sports television said teams would be told officially at a meeting of the F1 commission on Thursday that the third round of the season would be in Portugal.
Sources told Reuters the news, first reported by motorsport.com, was correct.
The Algarve circuit near Portimao hosted a grand prix for the first time last October on a heavily revised calendar due to the COVID-19 pandemic.
The return would have been confirmed last month but that was thrown into doubt by the country seeing a spike in cases and imposing a nationwide lockdown.
Bahrain, which opens the season on March 28, could have hosted two successive races if the plans for Portugal had been cancelled.
The Portuguese Grand Prix will be on the weekend before the Spanish round at Barcelona’s Circuit de Catalunya.
That would mean the mostly British-based teams would stay abroad, avoiding the need for a period of hotel quarantine that would arise under present rules if they returned directly from Portugal.
Portugal is on Britain’s « red list » of countries with a heightened risk.
F1 personnel have to undergo regular testing during the season, with teams operating in protective bubbles at racetracks.
New F1 chief executive Stefano Domenicali said last week that the sport still aimed for a record 23 races this year after holding just 17 last season.
https://www.espn.com/f1/story/_/id/30873960/portugese-grand-prix-return-f1-calendar-2021