"Mila and I would like to welcome Wyatt Isabelle Kutcher to the world. May your life be filled with wonder, love, laughter, health, happiness, curiosity, and privacy," Kutcher wrote on his website Thursday.
The actor also included photos of six babies, a llama and a dog, teasing: "Can you guess which one is ours, or does it really matter? All babies are cute."
Kunis gave birth to Wyatt on Tuesday, according to TMZ, which first reported the news. This is the first child for her and Kutcher.
Kutcher was previously married to Demi Moore.
Gotham's Robin Lord Taylor on becoming the villainous Penguin: