The reality TV star told E! News that her second child with boyfriend Scott Disick was born early Sunday at Cedars-Sinai Medical Center and weighed 7 pounds, 14 ounces. Her full name is Penelope Scotland Disick.
Kardashian said mother and child were "resting comfortably."
She and Disick have a 2-year-old son named Mason. Both of her pregnancies were highly publicized.
Her sister, Kim, wrote on her website that the family was thrilled to finally meet the newborn. The family appears on "Keeping Up With the Kardashians."