The 30-year-old Australian and 36-year-old American Dancing with the Stars pros marked the occasion by dedicating intimate posts to each other on social media.
"To my best friend, with whom I get to spend the rest of my life with..... You are everything that I've always dreamed of and I can't wait for the next 50 years where I can fall asleep beside you and fall in love all over again #happyanniversary #inlove #soontobethree," Murgatroyd captioned a photo of herself and Chmerkovskiy in bed.
"Thank you @RestaurantDaniel and your incredible staff for our amazing first anniversary dinner! @petamurgatroyd loved it so much we're looking forward to making this our annual tradition #InLoveWithThisChick #TodayWasAnAmazingDay #HadToTryDesert #CardioDayTomorrow," Chmerkovskiy added to a picture of himself and Murgatroyd locking lips.
Chmerkovskiy proposed to Murgatroyd onstage Dec. 5, 2015, following their performance in the show SWAY: A Dance Trilogy. The couple confirmed in June that Murgatroyd is pregnant and expecting their first child.
"I can't wait to provide this baby with the tools to become a beautiful, kind person," Chmerkovskiy told People the same month. "And they'll have the best sneaker collection."
"I'm looking forward to nurturing something and just having the baby be the center of our world," Murgatroyd added. "I'm looking forward to putting all our energy into this beautiful soul."
Murgatroyd and Chmerkovskiy met on Dancing with the Stars in 2011. Murgatroyd sat out Season 23 due to her pregnancy, but Chmerkovskiy was partnered with television personality Amber Rose.