The couple also shared a photo of their baby daughter – hidden amongst snaps of another five newborns!
Can you spot baby Wyatt amongst the cute collection below? No, us neither – and proud dad Ashton isn't telling!The 36-year-old revealed his daughter's name on his website and added that he hopes her life will be filled with 'wonder', 'love' and 'privacy'.
He wrote: "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."
And with the latter in mind, he seems determined to keep Wyatt's identity a mystery by teasing fans with a collection of cute baby photos (plus a llama and a shaggy dog - seriously!) and asking them to guess which of the babies is theirs.
He joked: "Can you guess which one is ours, or does it really matter? All babies are cute."
On his Facebook page, he added: "Here's your baby photo. Well, one of them is. Now can the helicopter please stop hovering over our house, there is a baby sleeping inside! And she's super cute."
According to our Baby Names Generator, 'Wyatt' is an English boy's name which means 'guide'. Isabelle, of course, is more traditional and is a variant of 'Elizabeth', meaning 'God of plenty'
Mila, 31, started dating her former That 70s Show co-star in 2012, and got engaged to him earlier this year. She birth at Cedars-Sinai Medical Centre in Los Angeles on Tuesday night, with Ashton right by her side.
A source close to the couple told gossip website TMZ.com that the pair were taken straight into the delivery room after arriving at the hospital at 6am on Tuesday morning.
The insider said they arrived alone, without any family members or assistants.
The couple were last pictured in public together over the weekend when they took their two dogs for a walk in a Hollywood park, while in the lead up to the birth Mila was regularly seen attending pre-natal yoga classes.
Speaking about what she wanted her kids to be like, Mila recently told Marie Claire magazine: "I just don't want my kids to be a**holes. I feel like so many kids are nowadays.
"Both of us just want to have well behaved honest, nice children who people meet and say, 'That's a good kid'."
See if you can guess which baby belongs to Mila and Ashton from the gallery below...