But you can hold off on the cards and gifts – she's not expecting baby number two.
The actress, 35, was snapped on the set of her new film Woman In Gold wearing a prosthetic pregnancy belly.
Holmes, who is mom to daughter Suri Cruise, 8, stayed in character while taking a break from shooting the film, opting to keep the prosthetic bump on as she walked around set and grabbed a snack from craft services.
She plays the wife of Ryan Reynolds in the movie, which tells the story of a Holocaust survivor who takes on the government to recover artwork she believes belongs to her family.
The film, which is slated for release next year, also stars Helen Mirren and Elizabeth McGovern.