Kourtney Kardashian gives birth to baby girl
The couple, who are already parents to son Mason, 2, have named their new daughter Penelope Scotland.
Kourtney, 33, told E! News: "Scott and I are overjoyed to welcome our precious angel Penelope Scotland Disick into our lives.
"We are forever blessed. Mommy and baby are resting comfortably.
"Penelope was born in LA's Cedars-Sinai Medical Center on Sunday and weighted a healthy seven pounds and 14 ounces.
Kourtney's mum, Kris, says her daughter had a natural birth and described the delivery as 'easy'.
Younger sister Kim, 31, who dates rapper Kanye West, has posted a congratulatory message on her official website.
She wrote: "Welcome to the world, Penelope Scotland Disick!
"Kourtney gave birth to a beautiful baby daughter on Sunday and the whole family is so thrilled to finally meet her! She is absolutely perfect!
"I am so excited to be an aunt again and can’t wait to spoil little Penelope.
"I know Mason is going to be the best big brother in the whole world. Congratulations Kourtney and Scott. Xo."