The adorable picture shows the baby wearing a cute onesie as he appears sound asleep with his arms raised above his head.
Mrs West revealed that she chose “today” to share Saint’s picture because it is her late father, Robert Kardashian’s birthday.
“Today is my dad’s birthday. I know there’s nothing more in the world he would have wanted than to meet his grandchildren. So I wanted to share this pic of Saint with you all,” the proud mom-of-two wrote.
Kim had earlier this month teased fans with a picture of Saint’s hand wrapped around big sister, North West’s finger.
“She said ‘He’s my best friend’,” the socialite captioned the picture.
Kim and her rapper husband, Kanye West, welcomed their son on December 5, 2015.