The actor, who stars as Madeline Ashton in the Broadway revival, announced she's taking a break due to a vocal condition.
In order to preserve her voice, she's decided to step away from the character - famously portrayed by Meryl Streep in the 1992 film - "for three to four weeks".
"Madeline Ashton is by far the most challenging and rewarding role I have ever taken on," Hilty wrote on Instagram.
"The lengths to which I have gone to make sure I can physically do the show is a job in itself.
"It's hard for me to admit I am human, particularly because performers are often asked to push through and pretend that we're not," the Smash singer continued.
"I am so fortunate to work with the best producers, company and stage managers, who don't subscribe to that way of thinking and fully support me and my fellow castmates when our bodies tell us it's time for a break."
The announcement comes days after Hilty performed the musical's fan-favourite song For the Gaze at the Tony Awards.
Hilty received a Tony nomination for her leading role.
