ET previously revealed that the pair got engaged in Oklahoma, where Shelton has a home, the weekend of Oct. 17.
They began dating in November 2015 after meeting as coaches on The Voice. Their romance came shortly after both musicians had gone through high-profile splits from their spouses, Shelton with country singer Miranda Lambert and Stefani with rocker Gavin Rossdale.
The couple took home a joint CMT Music Award earlier this month and Shelton opened up to ET about their journey together.
"We've been together now for five years, believe it or not. We've worked together and we've written together," Shelton explained. "So at this point in our relationship, we're always looking for what's the next thing that we haven't accomplished yet."