The 33-year-old "Glee" alum will play the role of Eddie originally portrayed by Meat Loaf in the cult 1975 film, said The Hollywood Reporter.
"I grew up watching 'Rocky Horror,' but could never imagine that I would be part of this new vision. 'Rocky Horror' always made me feel like it was OK to celebrate my weirdness. Hallelujah, bless my soul! I love that old time rock-n-roll!," Lambert said.
Eddie is the rock 'n' roll-loving ex-delivery boy, who emerges at Dr Frank-N-Furter's on a motorcycle and crashes the party.
The roles were originated by Susan Sarandon and Barry Bostwick.
The two-hour special, will be directed, executive produced and choreographed by Kenny Ortega.
The new version will be produced by Fox 21 Television Studios and Berman's The Jackal Group.