Selig, a member of the ensemble, will continue in the role through Feb. 21. He succeeds Gavin Creel.
"South Park" creators-writers Trey Parker and Matt Stone and Tony-winning Avenue Q songwriter Robert Lopez collaborated on the script and score to the musical, which earned Tony Awards for Best Book, Best Score and Best Musical.
Co-directed by Parker and Casey Nicholaw, The Book of Mormon opened to critical acclaim March 24, 2011, at the Eugene O'Neill Theatre. Both earned Tony Awards for their work.
The Book of Mormon has set design by Scott Pask, costume design by Ann Roth, lighting design by Brian MacDevitt and sound design by Brian Ronan. Orchestrations are by Larry Hochman and Stephen Oremus. Music direction and vocal arrangements are by Stephen Oremus.