The stars, who have been dogged by marriage rumours for years, announced the happy news via Instagram on Tuesday (27Oct20), with the No Doubt star sharing a photo of herself kissing her new fiance as she showed off her engagement ring.
"@blakeshelton yes please!" she captioned the picture, adding a diamond ring and prayer hands emojis, while country singer Shelton reposted the image and wrote, "Hey @gwenstefani thanks for saving my 2020... And the rest of my life... I love you. I heard a YES!"
The musicians, who met on the set of U.S. talent show "The Voice" in 2015, were inundated with celebratory messages from fans and celebrity friends, with fellow TV judge John Legend commenting, "AMAZING! Congratulations to you both!!"
"WOWWWWWWW CONGRAAAAAATS (sic)," added Ryan Tedder, while Garbage, UB40, and a representative for "The Voice" also offered their well wishes.
The news emerges weeks after Stefani admitted she doesn't mind when people refer to Shelton as her "husband" even though they aren't married - but confessed the couple had no plans to wed at the time.
"Do you know how many people say my 'husband' about him," she smiled as she spoke to "Jimmy Kimmel Live!" guest host Dua Lipa in early October. "I guess we're just together... people got used to it or something like that, but it's pretty cute."
Meanwhile, it will be Shelton's third trip down the aisle after unions to Kaynette Williams and second wife Miranda Lambert, who he divorced in 2015 after four years of marriage.