“Happy Birthday to my King,” Kim, 39, wrote alongside two photos of the couple, dressed in all black and sharing a kiss.
The post received comments from the likes of Paris Hilton, who replied, “Happy Birthday Kanye! ????,” and Skai Jackson, who left a red heart emoji.
Kim also shared sweet words for Kanye on her Instagram Stories, where she shared more couples photos, as well as funny snaps of the musician with their son, Saint.
"Thank you for always being you and never letting the world change who you are!" she wrote on one photo."Life wouldn't be the same without you!"
The rapper’s mother-in-law, Kris Jenner, also celebrated West on social media.
“Happy Birthday #KanyeWest!!” she captioned a slideshow of images of the singer. “You are an amazing son, father, husband, uncle, brother and friend... thank you for being such a special and important part of our family... I love you very much ?❤️????.”