Former pro castmember Julianne Hough and LMFAO's Redfoo are additionally billed to join the regular judges this season.
Robin Roberts (II) is tapped as a guest judge on "Dancing with the Stars" next week. The "Good Morning America" anchor will join regular judges Len Goodman, Bruno Tonioli and Carrie Ann Inaba on the third episode of season 18 aired on Monday, March 31.
Len, Bruno and Carrie Ann announced Robin as the first-ever "DWTS" celebrity guest judge on "GMA" Tuesday. During their appearance, Len suggested Robin, who admitted to being "nervous" about her upcoming judging stint, to be "honest."
Julianne Hough, who is a former pro dancer on the show, will also return as a guest judge on April 7. She previously filled in for Len in October 2013. Other guest judges this season include singer Ricky Martin and LMFAO's member Redfoo.
The third week of "DWTS" season 18 will feature the "Switch Up" challenge, in which the stars and pros will switch partners for a week. Fans can help determine the new pairings via Twitter.