Sieber is a two-time Tony Award-nominee best known for his work in the Broadway shows "Monty Python's Spamalot" and "Shrek The Musical."
Sieber is to begin performances as Georges March 15, starring opposite four-time Tony Award-winner Harvey Fierstein as Albin.
Georges will be played by understudy Chris Hoch through Sunday at Manhattan's Longacre Theatre.
Kelsey Grammer was the first actor to play the role in the current revival, which began its run last year. Jeffrey Tambor briefly took over the role last month after Grammer's stint ended, but a bad back forced Tambor to drop out of the production.