Mr Johnson, 55, was taken to St Thomas’ hospital, in London, on Sunday – 10 days after testing positive for the virus.
He had three nights in intensive care before returning to a ward on Thursday.
Downing Street said the PM would continue his recovery at his country residence, Chequers.
“On the advice of his medical team, the PM will not be immediately returning to work. He wishes to thank everybody at St Thomas’ for the brilliant care he has received.
“All of his thoughts are with those affected by this illness,” the statement added.