The Commons leader tweeted that his child was tested last weekend and the household is isolating while awaiting the result.
He also thanked Conservative MP Stuart Andrew for standing in for him at business questions.
Many thanks to @StuartAndrew for standing in for me at Business Questions. One of my children was tested for COVID-19 last weekend after displaying symptoms. In accordance with government guidance, the household has been in self-isolation while we await the test result.— Jacob Rees-Mogg (@Jacob_Rees_Mogg) September 10, 2020
His tweet comes as the government came under fire for its testing programme.
Sarah-Jane Marsh, one of the experts on the test and trace team, apologised to people struggling to get a test as the system struggles to cope with demand earlier this week.
In a tweet, she said: “Can I please offer my heartfelt apologies to anyone who cannot get a COVID-19 test at present.
“All of our testing sites have capacity, which is why they don’t look overcrowded, its our laboratory processing that is the critical pinch-point.
“We are doing all we can to expand quickly.”
SNP Commons leader Tommy Sheppard wished Rees-Mogg and his family well and joked: “After five long months of my own absence from this chamber, and sometimes problematic communication through the virtual proceedings, I have been looking forward to being patronised in the flesh rather than over the internet.”
Rees-Mogg has had responsibility for resuming parliament in a safe way amid the pandemic.
He has previously said he was “very keen” to see more than the current maximum of 50 MPs be allowed into the House of Commons chamber, and said the current official advice restricted the attendance.
Many representatives call in by Zoom to ask questions and participate.
Speaking earlier in September, Rees-Mogg said: “I am really keen that this chamber should be as full as it possibly and safely can be, and Mr Speaker I’m sure you saw the comments in the debate last night – people saying can we use the galleries, can we have microphones at the crossbenches at the back, can we do things to get more people in?
“I’m very keen we should, I think Mr Speaker I can speak for you and say you are keen that we should, but we slightly run up against the official advice from PHE (Public Health England) and it is difficult for this house, of all places, to ignore the advice that is being given by an official body.
“That is where we are slightly stymied but perhaps they will be more flexible, then I know Mr Speaker will encourage more people to come in.”
The speaker of the House of Commons, Sir Lindsay Hoyle, said he and Rees-Mogg had ruled out the use of masks, which would allow MPs to sit closer than two metres apart, because it would make it harder to recognise people and to read speeches.
Hoyle said, in an interview with Times Radio, that he had been lobbying for daily testing for MPs which would allow for more participation in debates.
Coronavirus: what happened today