Cardi B announced the Tuesday birth of her daughter Wednesday on her official Instagram account.
"Kulture Kiari Cephus 07/10/18 @offset," the caption read on a photo showing the rapper nude and very pregnant.
It's the 25-year-old's first child with husband and fellow rapper Offset, whose legal name is Kiari Kendrell Cephus.
Cardi B kept her pregnancy under wraps before going public in April during an appearance as the musical guest on "Saturday Night Live."
They announced then that they were expecting a girl.
She and her husband, a member of hip hop trio Migos, have actually proved to be pretty adept at keeping secrets. Cardi B recently revealed that the couple secretly married last September at their home in Atlanta.
Fans believed they were only engaged as Offset dropped to one knee last October at a concert for a very public proposal.
Cardi B explained that they simply wanted privacy.
"There are so many moments that I share with the world and then there are moments that I want to keep for myself," she wrote on social media. "Getting married was one of those moments!"