The actress and author, 34, is expecting her first child with husband Christopher Jarecki later this year, her rep tells PEOPLE exclusively.
"I've been wanting to have a baby since I was 2 years old – I'm destined to be a mother," Silverstone said in April.
She and Jarecki, 40, wed in June 2005 in Lake Tahoe after eight years together.
The author of vegan cookbook The Kind Diet, Silverstone will next be seen in the films Vamps, Butter and Homework.
Reporting by JULIE JORDAN