Mirren is expected to star in the New York transfer of Peter Morgan's drama The Audience.
The Cabaret director was honored at the Hammerstein Ballroom with the Jason Robards Award for Excellence in Theatre.
England's only audience-choice awards were also bestowed upon the likes of Helen Mirren, Haydn Gwynne, and Michael Grandage.
The British actress will be presented with the fellowship on February 16.
Harris joins the company of Dame Helen Mirren, the Pudding's 2014 Woman of the Year, for the Ivy League cross-dressing extravaganza.
Gavin Creel, Helen Mirren, James McAvoy, and more join the wizards as this year's WhatsOnStage Awards nominees.