The 40-year-old country star gushed about the "hot" but "grounded" singer while appearing on Friday's episode of "The Ellen DeGeneres Show."
"I love talking about Gwen," Shelton told DeGeneres. "It's been just an eye-opener to be with somebody like her."
"Believe it or not, you think Gwen Stefani and No Doubt, and she's literally maybe the most normal person I have ever met in my life," he said. "It's been good for me to be with somebody that's so grounded and a good human being with a great heart.
"And she's hot. Have you seen her?" the star jokingly added.
Shelton and Stefani confirmed their relationship in November 2015 after splitting from their respective spouses, Miranda Lambert and Gavin Rossdale, earlier in the year.
Stefani was equally complimentary of Shelton at the 2016 Glamour Women of the Year Awards in November.
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"This year was like someone said, 'Hey, wake up!' and I was like, 'Whoa! Oh my God!' I thought I was seeing color but now I'm really seeing in color," the singer said. "I didn't know I was in a cocoon ready to bust out."
Shelton and Stefani initially met on "The Voice" in 2014, and will both appear as coaches on the NBC reality competition's upcoming 12th season.
The country star last released the album If I'm Honest in May, which includes the song "Go Ahead and Break my Heart" featuring Stefani.
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