In a video posted to Facebook, Nugent, 72, said he had had "flu symptoms for the last 10 days" and "thought I was dying."
"I was tested positive today," Nugent told fans in video that appeared to have been recorded at his Michigan ranch.
"I got a stuffed up head, body aches, oh my god what a pain in the a--. I literally can hardly crawl out of bed, the last few days but I did. I crawled."
Nugent appeared to say he will follow orders to remain in isolation: "I'm homebound, i.e. quarantine."
Throughout his 8-minute, 50-second video, Nugent used racist language to describe the virus, which had killed more than 570,000 people in the U.S. as of Tuesday morning, according to a running tally by NBC News.
Just four months ago, Nugent doubted that the coronavirus even existed, calling it a "scamming pandemic" and vowing not to take any vaccine.
"It's not a real pandemic and that's not a real vaccine. I'm sorry, I ain't taking no vaccine," Nugent told fans in a video on Christmas Day.
"You come at me with a needle and I will be in fear of my life," he said. "You know what I'll do if you come at me with a needle: 'Hi, I'm from the government, this needle's good for you.' F--- you."