At the end of the competition only one artist and their protégé will be left standing, with the amateur singer scooping a recording contract with Hollywood Records.
Casting information is available at www.abc.com/casting.
Clarkson said: "The simple fact that I get to go out and find two people that I believe in, sing with them every week, and help them accomplish their dream is an amazing thing that I can't wait to be a part of!"
Sugarland singer Nettles called the show's concept "fresh" because it will allow her to actively mentor her contestants. "Most of my greatest learning was from singing and playing with other performers throughout my life and career," she said.
"To have had the opportunity to perform with an established artist would have been so incredible when I was up and coming."
Richie said he was excited to start working with his newfound talent, saying his goal is to "develop true artistry and give them the tools necessary to be creative artists instead of created artists".
He added: "I am eager to pass along a few of the nuggets of wisdom that I have received throughout my 40-year career from my own mentors, such as Marvin Gaye, Frank Sinatra, Sammy Davis, Quincy Jones and Stevie Wonder."
Thicke said: "I'm truly excited to be a part of Duets. The format is unlike anything that's out there right now, and the opportunity to work with such talent, both the other artists and contestants, is definitely going to make for an exciting competition."