The actress revealed her big news on social media yesterday
She is already mum to three-year-old Jonathan, but Anne Hathaway is expanding her brood.
The Oscar-winning actress made the announcement on Instagram, where she revealed that she and her husband of seven years, Adam Shulman, had struggled with fertility problems.
"It's not for a movie...#2," she said, captioning a photo of herself in the mirror with a visible baby bump. "All kidding aside, for everyone going through infertility and conception hell, please know it was not a straight line to either of my pregnancies. Sending you extra love."
The notoriously private star has not revealed details about her due date or the sex of the baby.
Forthcoming roles include The Grand High Witch in Robert Zemeckis's adaptation of Roald Dahl's 'The Witches', set for release next year. She is also believed to be in pre-production for a movie version of 'Sesame Street', scheduled for release in 2021.