O'Malley was born in Cleveland, Ohio, and was brought up by his single mother, who is of Irish ancestry. He grew up Catholic. He graduated from Saint Ignatius High School in Cleveland, Ohio and Carnegie Mellon University. O'Malley became friends with Josh Gad and Leslie Odom, Jr. at Carnegie Mellon University and remain good friends.
Awards and Nominations
- 2011 Tony Award for Best Featured Actor in a Musical
- 2011 Drama Desk Award for Outstanding Featured Actor in a Musical
- 2016 Broadway.com Audience Award for Favorite Replacement (Male)