He kept a journal of celebrities, family, and friends' signatures in his dressing room during Spring Awakening.
If Jonathan had not become an actor, he would have been a teacher.
Jonathan's three favorite television shows are Alias, Lost, and I Love Lucy.
His special talent, besides acting, singing, and dancing, is distance running.
In his winter coat he always carries a seashell that his voice teacher's daughter sold to him because it helps him stay calm.
His celebrity obsession is Jennifer Garner and Spring Awakening costar Lea Michele has said that if she comes to see the show, Jonathan will cry, if not have a heart attack.
In the 2007 Macy's Thanksgiving Day Parade, Jonathan performed "Send My Regards to Broadway" with his Spring Awakening costar Lea Michele.
Jonathan had intended to audition for colleges when he moved to the city but was cast in the national tour of The Sound of Music before he began college auditions.
He first became interested in musical theater through Disney movies such as Mary Poppins, which he watched six times a day when he was three years old.
He had known of Michael Mayer, director of Spring Awakening because of his obsession with Thoroughly Modern Millie, which he directed in 2002 and Jonathan went to see six times.
The first theater role Jonathan ever had was Teddy Best in a show called "Best in the West" that he did in eighth grade.
When he was cast as Melchior in Spring Awakening, he bought all of Duncan Sheik's albums to familiarize himself with the composer of the show.
One of Jonathan's summer jobs was being the voice of the Wishing Well at Dutch Wonderland, an amusement park near Lancaster, Pennsylvania.
Two essentials that he kept in his Spring Awakening dressing room were a curling iron and a framed picture of his family.
Jonathan used to work at the Chelsea Grill of Hell's Kitchen in New York and still considers it a favorite restaurant of his.
One of Jonathan's summer jobs was being a camp counselor.
Outside of his theatre roles, Jonathan does not curse in his everyday life.
Jonathan performed with Lea Michele at the 2007 Macy's Thanksgiving Day Parade in New York.
Jonathan considers Sutton Foster to be an inspiration to him.
In high school, Jonathan was involved in theatre and played parts in How to Succeed in Business..., Kiss Me Kate, Godspell, and You're a Good Man, Charlie Brown.
Jonathan says that his mother often brings a "Menanite Bus," people from his hometown, to see Spring Awakening on Broadway.
Lea Michele has said about Jonathan that, "Jonathan's so good, he's so wonderful, he takes time to talk to everyone."
Jonathan Groff: When I was living in PA, my mom and brother and I used to go to dinner and a movie for every mother's day! This year, since I can't be at home, I'm going to send my mom a picture of us on the The View with Rosie, because she is obsessed with that show and with Rosie!