Reality TV star Kourtney Kardashian and her partner Scott Disick have named their newborn son Reign Aston Disick.

The 35-year-old, who delivered her third child Dec 14, posted an image of her son's hand on Instagram Sunday, reports people.com.

`Madly in love with my little Reign Aston Disick,` the `Keeping Up with the Kardashians` star captioned the image.

The newborn's birthday co-incidentally falls on the same day as the couple's five-year-old son Mason.

The couple also have a two-year-old daughter, Penelope Scotland.