The actress showed off her new bling on her social media.
The couple got engaged while spending time with family in Snowmass, Colorado, over the holiday break. The 31-year-old Search Party actress shared the exciting news on her Instagram earlier this week, posting a slideshow with photos of herself and her new fiance, as well as a snowy pic of her gorgeous round diamond halo engagement ring.
"The love of my dang life proposed to me," she wrote alongside photos of the two of them. "He is the best guy in the world. It was an epic surprise surrounded by our closest family and I would give the proposal 5 stars on yelp!!!!!"
Russell, 32, and Hagner met on the set of the 2016 indie film Folk Hero & Funny Guy. The actor's parents, Goldie Hawn and Kurt Russell, also fell in love while working together on Swing Shift in 1983.
This will be Russell's second marriage. He and stylist Sanne Hamer tied the knot in March of 2014, separated in March 2015 and divorced in 2017.
The couple isn't the only celebrities to get engaged over the holiday. Heidi Klum's boyfriend, Tom Kaulitz, proposed to her earlier this week. Debby Ryan got a stunning sparkler from Twenty One Pilots' beau Josh Dun and Robin Thicke asked his pregnant girlfriend, April Love Geary, for her hand in marriage.
See who else is taking the next step in their relationship in the video below.