The singer announced their exciting news on Instagram by posting a picture of himself kissing Chloe's growing bump.
Alongside the snapshot, JB also posted two emojicons on tiny footprints and a baby's face. Aww!
JB's bandmates and friends have been quick to congratulate the couple on their pregnancy, with Marvin Humes tweeting: So so so excited! @JBGill and @ChloeSGill are expecting a baby!!!!!!!!! Boom! Congrats guys!x."
Marvin's wife Rochelle also posted: "@ChloeSGill @JBGill You don't understand how excited Auntie Roch is...I nearly burst with excitement! Love you guys too much."
Meanwhile, bandmate Oritsé Williams tweeted: "Massive congrats to my boy @JBGill & @ChloeSGill !!! #BubbaGILLOnTheWayYaaayyyyyyy xxxxxxxXXXXxxxxxxxx."
Just last month, JB and Chloe got married in a lavish ceremony at Mount Stuart country house on the Isle of Bute.
Later, JB - real name Jonathan Benjamin - tweeted: "Thank you all so much for your amazing messages of congratulations. Can honestly say that was the #Bestdayofmylife xx."
Celebrities who have announced pregnancies in 2014:
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