While Her Majesty, 93, and Mr Johnson, 55, have met on a number of occasions throughout his eight years as London Mayor, it was found that he is distantly related to the Royal Family.
The BBC’s ‘Who Do You Think You Are?’ programme discovered in 2008 that Mr Johnson’s paternal grandmother Yvonne Eileen Irene Williams (nicknamed ‘Granny Butter) whose family name was de Pfeffel, was a descendent of Prince Paul Von Wurttemberg.
Yvonne’s great grandparents were Baron Charles de Pfeffel and Karoline von Rottenburg.
Karoline was the illegitimate daughter of Prince Paul von Wurttermberg and an actress named Friederike Margrethe Porth.
In turn, Prince Paul was a great-great grandson of King George II, who reigned from 1727 until 1760.
Speaking on the programme at the time, Mr Johnson said: "If you had told me that I was related to George II, I would have thought you were absolutely crackers," he said.
"I would have been terribly proud just to have been related to the German King, but I can't hide it from you that even in our common European home, I am particularly thrilled to have some British Royal ancestry as well."
The Tory leader also shares something else in common with the Royal Family. He studied at Eton College, like the Queen’s grandchildren Prince William and Prince Harry, who were the first royals to attend the boys' boarding school in Windsor.
Mr Johnson was named Tory leader on Tuesday, securing 66% of Conservative Party’s members’ votes to defeat challenger Jeremy Hunt.
He will officially become prime minister on Wednesday after Theresa May tenders her resignation to the Queen and he follows her to Buckingham Palace to ask to form his own government.