Mel Gibson is officially an octodad.
Grigorieva, 39, gave birth a few weeks before her December due date.
Gibson, 53, announced the brunette songbird's pregnancy on "The Tonight Show" in May when he revealed that he and his soon-to-be-ex wife Robyn had been separated for "three years." She filed for divorce from the actor in April after 28 years of marriage.
The couple has seven kids together -- six sons and one daughter.
"I guess I'm Octo-Mel," he joked on the show.