In an Instagram post, Kylie posted an image of her holding her daughter's hand with the caption: "Stormi", reports the thesun.co.uk.
Kylie posted the full name of the child . It reads "Stormi Webster".
Although Kylie and her boyfriend Travis Scott have yet to reveal the reason they chose the moniker, some baby name websites say the name means having "charm" and being able to "attract money".
Another website claims Stormi means someone who is a "free spirit" and has the "biggest heart".
Kylie announced on Sunday that her child with Scott was born on February 1 and apologised for keeping her pregnancy secret from her 101 million Instagram followers and other fans.
Stormi is the second of three additions to the Kardashian clan this year. Half-sister Kim Kardashian and her rapper husband Kanye West announced the arrival in January of their third child -- Chicago.
Stormi joins Kardashian cousins North, Saint, Reign, Dream, Mason and Penelope.