Mr Meadows works closely with the president and both senior administration and campaign officials.
He tested positive on Wednesday, according to reports, and hours earlier was in attendance at the crowded election night event at the White House — where few people wore masks — as well as spending time in the residence.
Footage from the night shows him entering the event with the president’s adult children and their partners.
Bloomberg reports that a Trump campaign aide, Nick Trainer, is also infected, plus another three people.
Efforts were made to keep Mr Meadows’ diagnosis a secret, according to Bloomberg’s White House correspondent Jennifer Jacobs, who also broke the news of Hope Hicks testing positive in October.
Mr Meadows has doubted the efficacy of masks and has refused to wear one on camera when talking to reporters, claiming that he was tested so often that he did not need to.
In an appearance on CNN’s State of the Union, he told Jake Tapper: “We are not going to control the pandemic … What we need to do is make sure we have the proper mitigation factors to make sure people don’t die.”
Mr Meadows has reportedly been closely involved in the campaign’s post-election response to the vote count and met with both vice president Mike Pence and presidential adviser Jared Kushner on Wednesday at campaign headquarters in Virginia.
He was also at the campaign offices on Tuesday with the president, in close proximity to unmasked staff.
Almost 40 people associated with the White House have now tested positive for the virus, including the president, first lady Melania Trump, and their son Barron.
Most appear to have been infected during the Rose Garden celebration announcing the nomination of Justice Amy Coney Barrett to the Supreme Court.
The news of Mr Meadows testing positive comes as the US sets a record for the number of new cases of Covid-19 for the third consecutive day with more than 122,000 documented on Friday.
There have now been 9.82 million confirmed cases of Covid-19 in the US, and 236,000 officially recorded deaths.
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