Mr Johnson, 56, exchanged vows with Ms Symonds, 33, in front of a handful of close friends and family, according to the Mail on Sunday,
He is the first prime minister to marry in office since Lord Liverpool married Mary Chester in 1822.
It comes just six days after the couple sent out save-the-date invites suggesting guests keep Saturday, July 30 free for their wedding .
When asked if the Prime Minister had wed one guest said: “You are not barking up the wrong tree. The couple will be making an announcement shortly.”
One No 10 aide said: “I have been strictly told not to comment.”
The couple’s 30 guests were invited at the last minute – with even Tory aides unware that the nuptials were going ahead.
The Sun reports that the church was cleared shortly after 1.30pm, with staff telling visitors it was being closed due to lockdown.
At about 2pm, a limo carrying the bride arrived. Classical music was said to be played as they walked down the aisle and exchanged vows.