Rugby player Ben announced their exciting news this afternoon, telling fans that their son - called Tadhg John - takes after his Saturdays star mummy.
Taking to Twitter, Ben said: "Tadhg John Foden has been born! Mum and baby are both amazing and healthy. He has a full head of hair and his mummy's lips! #babybenuna."
Irish singer Una announced her pregnancy in September and later embarked on an energetic tour with The Saturdays.
She and hubby Ben are already parents to two-year-old daughter Aoife Belle, and the tot is no doubt delighted to be a big sister!
Since announcing their news, Una's excited band mates have been tweeting their congratulations.
Vanessa White said: "Congratulations @UnaTheSats and @ben_foden on baby Tadgh!!! I can't wait to meet this little man!"
Rochelle Humes, meanwhile, added: "Tadhg John Foden has arrived. So so excited to have some Aunty Roch cuddles. Well done to my @UnaTheSats @ben_foden #lockupyourdaughters x."
The other girls are yet to spread the news, but we expect they are just as happy with the couple's lovely news.
Congratulations, Una and Ben!
Celebrities who have announced pregnancy news in 2015:
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