The couple, who are mum and dad to 16-month-old son Raphaël, are now expecting their second child together.
George has most recently been on the small screen playing Chris Noth's comely pregnant ethics expert on Blanc is founder of the French cinema information gatherer-provider Allo Ciné.
It's no secret that I've always wanted to be a mother, and every time I had a birthday I would just be a little bit sad.
You don't mind clicking over another number when you've got something inside you, growing, that you've always dreamed about."George, 37, was previously married to Claudio Dabed before divorcing in 2011, after which she briefly dated Russell Simmons.
The Australian-born actress and her French businessman boyfriend, Jean-David Blanc, welcomed their first child together on Monday.
George tweeted the happy news: "WELCOME TO THE WORLD!