The Austin Powers star and his wife Kelly welcomed daughter Sunday Molly on Friday, 11 April, according to People.
Mike and Kelly told the magazine they "couldn't be happier" about providing son Spike, two, with a sister.
The couple announced Kelly's pregnancy in October 2013, saying at the time they were "thrilled".
Mike and Kelly married in secret back in 2010, only revealing their happy news the following year. An international man of mystery, indeed!
They were together four years before tying the knot.
Mike's last movie appearance was in Shrek Forever After, where he voices the green ogre.
Congrats to Mike and Kelly!
Got an iPad or iPhone? Reveal Mag is specially designed to fit!
Celebrities who have welcomed babies in 2014 in pictures:
Copyright: Rex Features WENN/Matthew Taylor/Daniel Deme/Josiah True/Matthre Taylor/Joe