The American actress took to Twitter to announce her happy news, tweeting the very sweet message:
'Our family's so happy 2 announce tht 10/10/11 R baby girl Hattie Margaret McDermott was born at 7:08am.'
She then posted a super-cute shot of little Hattie's tiny tootsies.
New arrival Hattie weighed in at 6lb, 14oz and joins Tori, husband Dean and older siblings Liam, four, and Stella, three.
Congratulations - and what a lovely name!
Tori was regularly snapped out and about while pregnant - proudly showing off her growing baby bump on the beach like these other famous tums...