Bolsonaro confirmed the test results while wearing a mask and speaking to reporters in capital Brasilia, and said he is already taking hydroxychloroquine - an anti-malarial drug unproven to effectively treat COVID-19.
Under Bolsonaro, who has trivialized the raging pandemic and repeatedly flouted social distancing, coronavirus cases in Brazil have skyrocketed. the South American nation is now the 2nd-worst-hit country behind the United States, with over 65,000 deaths and 1.6 million confirmed cases. "On Monday, it got worse when I started feeling exhausted and some muscle pain".
On Monday, the far-right leader made more changes to weaken a law that would require citizens to wear face masks in public.
Over the weekend, Bolsonaro attended several events and was in close contact with the USA ambassador to Brazil during July 4 celebrations.
Reports of Bolsonaro's possible infection first emerged on Monday evening, with local news outlets reporting that he had been tested after developing coronavirus symptoms, including a 38C temperature and a persistent cough.
"I'm perfectly well", Bolsonaro told CNN Brasil in a live interview, after announcing the result of his test.
When the number of deaths in Brazil climbed past 5,000, Bolsonaro, whose middle name means messiah, said: "So what?"
In May, the country's Supreme Court published documents that showed that Bolsonaro tested negative thrice in March after meeting with the USA president, Donald Trump, in Florida. "I came from the hospital".
He has fired two health ministers during the crisis, both trained doctors, and replaced them with an active duty army general on an interim basis.
Unlike Britain's prime minister, who moderated his rhetoric after testing positive for the virus, Bolsonaro will probably not change his stance, said Leandro Consentino, a political science professor at Insper, a university in Sao Paulo.
Reuters reported that Bolsonaro said in a statement that he is home and in "good health".
This is the fourth coronavirus test he has taken - the first three had come back negative.
"He's going down a path of trying to indicate to his base of support that COVID-19 is just a little flu and take advantage of the illness to advertise for chloroquine", Consentino said. That day, Foreign Minister Ernesto Araujo tweeted an image from the lunch showing the president with his arm around the minister and seated beside the ambassador, Todd Chapman.