This is their first child since Boris Johnson stood down as Prime Minister.
The new baby joins siblings Wilfred and Romy, who were both born during Boris Johnson's term in office.
Carrie Johnson posted on Instagram that the family is "all very smitten" with the new addition.
Boris Johnson has four grown-up children from his previous marriage and another daughter from an affair.
He did not have any children with his first wife Allegra Mostyn-Owen.
LONDON DAILY ARCHIVE
Boris Johnson Becomes a Father for the Third Time with Birth of Son Frank Alfred Odysseus Johnson
Boris Johnson and his wife Carrie Johnson have announced the birth of their third child, a son named Frank Alfred Odysseus Johnson, on July 5th, 2022.
11 July 2023 · 16:00 UTC
