In 2014, Kinnunen auditioned for the role of Alyssa in a reading for The Prom. She ultimately was cast as the lead character, Emma Nolan, and went on to perform the role in Atlanta in 2016, before the show moved to Broadway in 2018. For this performance, she was nominated for a Tony Award for Best Performance by a Leading Actress in a Musical. Kinnunen and co-star McCalla's kiss during their performance at the 2018 Macy’s Thanksgiving Day Parade made national news as the first LGBT kiss in the parade's history. The production closed on August 11, 2019, after 23 previews and 309 regular performances.