"Thank you for the love you are sending our way. I have mild symptoms but overall feeling good. I am looking forward to a speedy recovery," she wrote.
The president is also experiencing mild symptoms, White House Chief of Staff Mark Meadows told reporters on Friday.
"As too many Americans have done this year, @potus & I are quarantining at home after testing positive for COVID-19," she said in another tweet. "We are feeling good & I have postponed all upcoming engagements. Please be sure you are staying safe & we will all get through this together."
The president tweeted early Friday that he and his wife both contracted COVID-19 Friday and will "begin" their "recovery process immediately."
"Tonight, @FLOTUS and I tested positive for COVID-19. We will begin our quarantine and recovery process immediately. We will get through this TOGETHER!" he said.
White House sources told Fox News that the two are doing "fine" after the news broke.
Trump's physician, Dr. Sean P. Conley, released a statement Friday saying he and the White House medical team will "maintain a vigilant watch."
“This evening I received confirmation that both President Trump and First Lady Melania Trump have tested positive for the SARS-coV-2- virus,” Conley said. “The President and First Lady are both well at this time, and they plan to remain at home within the White House during their convalescence.”
He added that he appreciates "the support provided by some of our country’s greatest medical professionals and institutions."