In a Snapchat message on Tuesday, the 40-year-old said she was feeling “so very blessed” and announced the name of her child, Pierre.
“We are overjoyed by the arrival of our little ray of sunshine, Pierre Kerr Spiegel,” she stated.
“We are ecstatic to welcome our fourth son into our household. I’m feeling incredibly fortunate.
The text appeared over a picture of blooming flowers, infant socks, and what appeared to be an article of apparel with the name Pierre stitched on it.
In September, Kerr—who is wed to Snapchat CEO Evan Spiegel—announced her fourth pregnancy.
The Australian gave birth to Flynn in 2011, and the two of them have a son. Orlando Bloom is her ex-husband.
From 2010 to 2013, she was wed to the Pirates of the Caribbean actor, who is currently partnered with Katy Perry and has a child together.