The French central defender had already been ruled out of the club’s Champions League ties through injuries and he is asymptomatic and said to be feeling fine, as outlined by Marca.
However, the positive result means the central defender has now entered a period of self-isolation and he will not be involved in training until he tests negative for the virus.
Umtiti had not travelled with the rest of the team to Lisbon due to his injury, while all those who are in the Portuguese capital have tested negative for the virus.
The Cameroon-born defender has lost his place in the France international side with Clement Lenglet – his Barca teammate – often preferred in both line-ups, while Gerard Pique is still first choice central defender at the Camp Nou.
His positive Covid-19 test result follows teammate Jean-Clair Todibo also testing positive this week.