Kim gave birth in Cedars-Sinai Medical Center in LA with boyfriend Kanye and her mother, Kris Jenner, by her side. Given the timing of the birth, Kim's daughter is being monitored in an incubator as a precaution and both mother and baby are said to be doing well.
"She has dark hair," a source told E News. "She looks just like Kim."
The new arrival is the icing on the cake for the overjoyed couple who have become one of hottest celebrity pairings thanks to a series of high octane appearances since they began dating a year ago.
Unlike her sister Kourtney, who shared the birth of her two children Mason, four, and Penelope, ten months, on their show Keeping Up With the Kardashians, Kim brought her daughter into the world without the presence of cameras.
In a recent magazine interview, the LA socialite explained that her attitude to privacy had changed because of Kanye.
She said she'd become "more of a recluse" while expecting as a way of "preparing to respect the privacy of my child and my boyfriend". In a Mothers' Day blog Kim also admitted to being "nervous and anxious" about the challenges ahead, but added: "I'm also excited knowing that I learned from the very best."
By the very best she meant her mother and manager Kris Jenner, who has six children and four stepchildren from two marriages.
Kim described the matriarch as "a strong and ambitious career woman" who "still manages to put family first and continues to look out for us every day". She also praised her big sister Kourtney as an "incredible mum".
"She is super woman with her ability to effortlessly balance work with taking care of two amazing kids," she went on. "I am so lucky to have her as my guide and confidant as I too become a mother."
The 32-year-old can also rely on the support of her devoted partner. What may seem like a whirlwind courtship actually comes after a decade-long friendship, during which they were each other's rock through bereavement and heartbreak.
Kim was there for the rap Midas man when his beloved mother Donda died in 2007. He in turn comforted her when she was criticised for breaking off her marriage to Kris Humphries after just 72 days.
Throughout the pregnancy, Kanye has been a pillar of strength, especially when his love was the target for negative comments about her maternity fashion and weight gain.
He serenaded her on stage during the Met Ball singing: "Don't let nobody bring you down/ You're so awesome/ You're so awesome."
Kanye West announced their baby news in a similarly adorable fashion, spilling the beans to fans at a New Year's Eve concert via an adapted version of his hard-hitting rap tune Runaway.
The original lyrics tell a hypothetical girlfriend to flee because of his commitment phobia.
In a softer ballad version for Kim, he adlibbed: "Even if it wasn't planned/God gave us a new plan/ Now you're having my baby/ And it means so much to me for us to raise a family".
Overcome with emotion, he finished by urging the 5,000-strong audience to "make some noise" for his "baby mama".