The 39-year-old reality star shared two snaps alongside her rapper spouse, flashing an uncharacteristically bright smile on the social media site, writing alongside them, "6 years down; forever to go. Until the end."
Kim also took to her Instagram Stories to share several pictures from her and Kanye's Italian wedding in 2014, writing the same caption.
Kanye didn't mark the occasion on his social media pages, but the pair received numerous messages from their famous friends on their special day.
"Happy Anniversary glad I've been there from the start!! You guys are the best," Kim's pal Jonathan Cheban added.
The couple are parents to four children - North, six, Saint, four, Chicago, two and 10-month-old Psalm.