McEnany announced she received the positive result Monday, but wasn't experiencing symptoms.
"With my recent positive test, I will begin the quarantine process and will continue working on behalf of the American people remotely," she wrote.
McEnany's positive test result follows several others in recent days -- including President Donald Trump himself, first lady Melania Trump, campaign manager Bill Stepien, former New Jersey Gov. Chris Christie and former White House senior adviser Kellyanne Conway.
Several others, including Republican Sens. Mike Lee of Utah and Thom Tillis of North Carolina, also tested positive after attending Judge Amy Coney Barrett's nomination ceremony at the White House late last month.
Meanwhile, New Jersey Gov. Phil Murphy said he would call for an investigation of whether Trump's campaign team violated health protocols by attending a fundraiser at Trump's golf course in Bedminster.
"The President and his staff acted recklessly in coming to New Jersey knowing that they had been exposed to someone with a confirmed positive test," Murphy tweeted Monday.
Presidential adviser Hope Hicks received a positive coronavirus test Wednesday, before Thursday's event held at the Trump National Golf Course.
State health officials and contact tracers are following up with 206 attendees and 19 staff members who were involved in both events, the governor said. He urged the state's attorney general to followup on any instances of the Trump team failing to comply with health rules.
The governor urged anyone who attended the Bedminster event, which was held indoors, to get tested and self-quarantine for 14 days.
Trump will be discharged from Walter Reed Army Medical Center in Bethesda, Md., Monday doctors said.
Vice President Mike Pence and second lady Karen Pence have previously tested negative, and were set to head to Salt Lake City Monday in advance of Wednesday's vice presidential debate at the University of Utah.