In the sweet snap, baby Saint, dressed in a white thermal onesie, is sound asleep as he lays with his arms up in the air.
"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," Kim wrote alongside her son's picture.
The "Keeping Up With The Kardashians" star, who gave birth to Saint on December 5 last year, had previously shared a photo of the little one's hand clasped around 2 and half year-old big sister North's finger.
The reality star and husband Kanye West, 38, had held off on sharing photos of their newborn immediately after his birth.