The couple announced their happy baby news on Thursday (17 March) as they attended the Eddie The Eagle premiere at London's Leicester Square.
Jools, 41, showed off her baby bump in a black jumpsuit as she walked with chef husband Jamie down the red carpet.
Jamie later confirmed the news with a retweet on his Twitter account.
Jamie and Jools, who have been married for 15 years, are already parents to daughters Poppy Honey Rosie, 14, Daisy Boo Pamela, 12, Petal Blossom Rainbow, six, and five-year-old son Buddy Bear Maurice.
A source told The Daily Mail: "Jools is radiant and blooming for the fifth time. The baby is expected in August."
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