The country superstar is the only coach who's been around for all 21 seasons, having spent 10 years in his spinning red chair. Ahead of Tuesday's Knockout performances, Blake and his fellow season 21 coaches -- Kelly Clarkson, John Legend and Ariana Grande -- marked the occasion with a massive Voice-themed cake and a celebratory group photo.
"Five hundred episodes old!" Blake marveled.
"You sure are!" Ariana teased.
ET even has a flashback to Blake and Voice host Carson Daly ahead of the series' premiere in 2011, where they joked about the star power of Blake's OG fellow coaches, Christina Aguilera, CeeLo Green and Adam Levine. Check out the full video above!
"Carson and I were looking at some of the pictures, and it was like, 'Oh my god. Look how young we are!'" Blake said of the flashback moment. "'Look how skinny I was back then! What happened to me?'"
Blake's had plenty of success on The Voice -- winning eight championships and meeting wife Gwen Stefani during his time on the show. However, even he admitted he was intimidated when Ariana joined the competition as a coach this season.
"It's embarrassing to follow her [onto the Voice stage]," Blake joked during the coaches' preseason press conference of the audience's enthusiasm for the "7 Rings" singer. "It exposes my lack of celebrity."
As a longtime "huge fan of The Voice," Ariana was humble about her possible advantages, but said she couldn't wait for fans to see how her season 21 team comes together.
"I have watched many seasons and I love watching the show," she said. "It always has the best energy. It's such wholesome, inspiring television, and I love seeing the different voices and watching so many people start careers for themselves. It's a beautiful, amazing thing."
See more in the video below. The Voice airs Mondays and Tuesdays at 8 p.m. PT/ET on NBC.