Now, 17 days after giving birth in Los Angeles, Kerr has gone public with the news.
Alongside a picture of a stuffed animal and wooden block letters spelling out Hart, Kerr wrote: “Thank you so much for all of your warm wishes. Evan, Flynn and I have been in baby bliss for the last 17 days with our new arrival, baby Hart.”
She added: “We feel so very blessed.”
News of the child’s birth broke earlier this month when it was reported Hart was born at Cedars-Sinai Medical Centre in Los Angeles.
This is the first child for Kerr and Spiegel, who married in May 2017.
Kerr, a former Victoria’s Secret Angel, has a seven-year-old son, Flynn, with her former partner, actor Orlando Bloom.
Miranda Kerr confirms the birth of her baby boy with adorable Instagram post