Bachchan's father Amitabh broke the news via Twitter, telling his followers: "I am going to become a grandfather! Aishwarya is expecting! So happy and thrilled!"
This will be the first child for Rai, 37, and actor Bachchan, 35. The couple wed on April 20, 2007 in a private ceremony at the Bachchan residence, Prateeksha, in Juhu, Mumbai.
Rai was crowned Miss World in 1994 and has often been referred to as "the most beautiful woman in the world." She has starred in more than 40 movies, including 2004's Bride and Prejudice and 2009's Pink Panther.