ABC said Helio Castroneves and Giles Marini will also appear on Monday's special 2-hour episode.
"The six remaining couples will each perform an iconic dance from the 'Dancing with the Stars' history vault and compete in a team dance," ABC said in a news release Thursday.
"Six former celebrities return as guest judges as they watch one of their iconic performances recreated on the dance floor. Helio Castroneves, Kelly Osbourne, Mel B, Drew Lachey, Giles Marini and Emmit Smith revisit the ballroom to act as a special 'fourth judge' in the dance competition. The second element of the show will be a team competition, and fan favorites and former Mirror Ball champions Apolo Anton Ono and Kristi Yamaguchi return as team captains."