Leclerc announced via Instagram on Thursday afternoon that he had contracted COVID-19, and was now self-isolating at home in Monaco.
"Hello guys, I hope you are all staying safe. I want to let you know that I have tested positive for COVID-19," Leclerc wrote.
"I am regularly checked according to my team's protocols. Unfortunately, I learned that I have been in contact with a positive case and immediately went into self-isolation, notifying anyone I had contact with.
"A subsequent test I took has come back positive.
"I am feeling OK and have milk symptoms. I will remain in isolation in my home in Monaco in compliance with the regulations set by the local health authorities.
"Stay safe and take care."
It is unclear where Leclerc contracted COVID-19, but he is known to have taken a holiday with his girlfriend to Dubai earlier this month.
He is the fifth F1 driver known to have tested positive for COVID-19. Racing Point drivers Sergio Perez and Lance Stroll missed races due after picking up the virus last year, with Nico Hulkenberg deputising on both occasions.
Seven-time world champion Lewis Hamilton was absent from the Sakhir Grand Prix in December after also contracting the virus, but returned for the season finale in Abu Dhabi after a swift recovery.
McLaren's Lando Norris revealed last week he had tested positive while on holiday in Dubai ahead of a winter training camp, and remains in isolation for another five days.
The Ferrari team issued a statement echoing Leclerc's message, confirming he was regularly tested in line with its protocols.
"Scuderia Ferrari Mission Winnow driver Charles Leclerc has tested positive for COVID-19," the team said.
"In accordance with the team's protocols, Charles is tested regularly and yesterday, the result from his latest test came back positive.
"Charles notified us immediately and has informed everyone he has been in close contact with in the last few days.
"He is currently feeling OK with mild symptoms and is now self-isolating at home in Monaco."