The Libertines frontman's girlfriend Edie Langley is expecting her first child with the rocker later this year and it is believed the new arrival will be a boy.
A friend of Edie posted on her Facebook page: "Over the moon for Edie Langley !!! havin a little boy! love you! xxx (sic)"
It is unclear when the couple's baby is due, though the pair were recently heard discussing impending parenthood as they travelled by bus to a hospital appointment in north London.
A fellow passenger told BANG Showbiz: "They seemed loved up and were holding hands as they discussed their appointment. Edie was telling Carl what they could expect when they met the midwife."
Carl and the Langley Sisters singer have been dating for around a year.
Though the musician hasn't got any children, his Libertines bandmate Pete Doherty recently admitted his son calls other members of the group "dad".
Pete admits six-year-old Astile - his child with former girlfriend Lisa Moorish - isn't a fan of his music and even gets confused when he sees his father with the rest of the group, co-frontman Carl, drummer Gary Powell and bassist John Halsall.
He said: "If I take my son to a gig he sticks his fingers in his ears and he calls the drummer 'daddy.' "